Atlanta mayor says she has tested positive

A pandemic of the novel coronavirus has now killed more than 535,000 people worldwide.

Over 11.5 million people across the globe have been diagnosed with COVID-19, the disease caused by the new respiratory virus, according to data compiled by the Center for Systems Science and Engineering at Johns Hopkins University. The actual numbers are believed to be much higher due to testing shortages, many unreported cases and suspicions that some governments are hiding the scope of their nations' outbreaks.

Since the first cases were detected in China in December, the United States has become the worst-affected country, with more than 2.9 million diagnosed cases and at least 130,101 deaths.

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Here's how the news developed on Monday. All times Eastern.

10:44 p.m.: Florida orders all schools to reopen despite rising cases

The Florida commissioner of education signed an emergency order Monday saying "all school boards and charter school governing boards must open brick and mortar schools at least five days per week for all students" when the new semester starts next month, despite the state's rising number of COVID-19 cases.

The commissioner said the order is subject to change based on future executive orders and the advice of local health departments.

The announcement was criticized by officials with Florida's largest labor union.

"It's clear in communications with our members that educators are scared. They don't trust politicians to make sure things are safe -- rightly so, with the record-breaking number of cases being reported," Fedrick Ingram, the president of the Florida Education Association said in a statement. "The governor is trying to brush that off. Safety for students and school employees needs to be at the center of our conversations about reopening schools."

6:46 p.m.: Atlanta mayor says she has tested positive

Atlanta Mayor Keisha Lance Bottoms announced that she has tested positive for the coronavirus.

"COVID-19 has literally hit home. I have had NO symptoms and have tested positive," the mayor said on Twitter Monday evening.

In an appearance on MSNBC Monday, Bottoms said that her husband has also tested positive for COVID-19. She and her family tested negative for the virus two weeks ago, she said, adding that she does not know how or when they were exposed.

Other U.S. politicians who have contracted the virus include Miami Mayor Francis Suarez, Georgia State Sen. Brandon Beach, Kentucky Sen. Rand Paul, Florida congressmen Mario Diaz-Balart and Shevrin Jones, Utah Rep. Ben McAdams and New York State Assembly members Helene Weinstein and Charles Barron.

As of Monday, the California Assembly also has five confirmed cases of COVID-19, the speaker's office told ABC News. One of those cases appears to be Assembly member Autumn Burke, who shared her diagnosis on Twitter Monday. The State Capitol will be closed for cleaning and sanitizing until July 13, the speaker's office said.

5:48 p.m.: Total cases in Florida double in two weeks

Total cases of COVID-19 have more than doubled in two weeks in Florida, state data shows.

On June 22, the Florida Department of Health reported 100,217 total cases since the start of the pandemic. On Monday, it reported 206,447 total cases. That means that since June 23, there have been 106,230 new cases in the state.

3:45 p.m.: California's positivity rate climbs, San Diego bars must close

As coronavirus cases rise in California, the state's positivity rate has climbed to 6.8%, Gov. Gavin Newsom said Monday.

California recorded 5,699 new cases of the coronavirus on Sunday, bringing the seven-day average to 7,876 cases, Newsom said at a news conference.

Hospitalizations are also increasing, Newsom said.

Twenty-three counties are now on Newsom's monitoring list, including Los Angeles and Sacramento, and newly added San Diego.

In those counties, bars must close, and restaurants and wineries must stop indoor operations.

Over the Fourth of July weekend the state's Department of Alcoholic Beverage Control visited nearly 6,000 restaurants and bars and issued 52 citations, Newsom said.

The "overwhelming majority ... were conducting themselves outstandingly," the governor said.

2:52 p.m.: Fauci says 'the current state is really not good'

As the U.S. battles the coronavirus pandemic, Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, says "the current state is really not good."

"We had been in a situation [where] we were averaging about 20,000 new cases a day," Fauci said in a livestream with NIH Director Francis Collins on Monday. "And then a series of circumstances associated with various states and cities trying to open up, in the sense of getting back to some form of normality, has led to a situation where we now have record-breaking cases."

Fauci said the average age of people getting infected now is 15 years younger than it was a few months ago, but young people must understand they aren't "in a vacuum."

"Innocently, they could infect someone who'd infect someone, and then all of a sudden someone's grandmother or grandfather, or aunt who's getting chemotherapy for breast cancer gets infected," he said. "You're part of the propagation of the pandemic so it's your responsibility to yourself, as well as to society, to avoid infection."

1:40 p.m.: Miami-Dade closing restaurants, gyms, rentals

As cases in Florida surge, Miami-Dade County Mayor Carlos Gimenez on Monday said he's signing an emergency order to close short-term rentals, gyms, party venues and restaurants, except for takeout and delivery.

The order will go into effect on Wednesday.

Beaches will open on Tuesday, but if there's crowding, Gimenez warned that he'll close them again.

"We are still tracking the spike in the number of cases involving 18- to 34-year-olds that began in mid-June, which the county's medical experts say was caused by a number of factors, including young people going to congested places -- indoors and outside -- without taking precautions such as wearing masks and practicing social distancing," Gimenez said. "Contributing to the positives in that age group, the doctors have told me, were graduation parties, gatherings at restaurants that turned into packed parties."

The average age of new cases is 21, according to Gov. Ron DeSantis, who said that may explain, in part, why the state's fatality rate is so low.

DeSantis also said the recent statewide surge is due to increased testing.

About 10% of the state's population has been tested for COVID-19.

He added, "part of the reason I think the fatality rate is lower is because you have better treatments today than you did in March. We brought a lot of hydroxychoroquine to Florida to have that as an option."

In June the FDA revoked emergency authorization for hydroxychloroquine to treat COVID-19, saying the evidence shows the recommended dose is unlikely to be effective against the virus.

"No need to be fearful," DeSantis said at a news conference. "There's some steps that individuals can take and that we're going to take statewide, but at the end of the day, this is something that has been around for quite some time."

12:40 p.m.: Harvard, Princeton announce back-to-school plans

Harvard will hold all courses online for undergraduate and graduate students for the 2020-2021 academic year, the university said Monday.

Some students will live on campus but will still take classes remotely, the university said.

The Faculty of Arts and Sciences is bringing up to 40% of undergraduates to campus, including all first-year students, for the fall semester. Assuming that density remains at 40% in the spring semester, Harvard said it plans to bring seniors back to campus, and freshmen would return home for the spring.

Meanwhile, Princeton announced Monday that it will bring roughly half of the undergraduate students back each semester.

Freshmen and juniors will come to campus in August and sophomores and seniors will return in the spring, the university said. Undergraduates have the option to spend the entire year remotely.

Most of the university's classes will be online, Princeton said.

12 p.m.: Arizona surpasses 100,000 cases

Arizona has become the eighth state to surpass 100,000 cases of the coronavirus.

As of Monday morning, 89% of Arizona's ICU beds are full, according to the state's Department of Health.

Arizona now has 3,212 patients in hospitals. At least 1,810 people in the state have died.

Arizona joins these states with more than 100,000 cases: New York, California, Florida, Texas, New Jersey, Illinois and Massachusetts.

10:33 a.m.: NYC has 1% positivity rate

New York City currently has a 1% positivity rate, Mayor Bill de Blasio said on Monday.

"At the height of this crisis," de Blasio said, 71% were testing positive.

Monday marks the start of New York City's phase 3 reopening which includes nail salons and spas, as well as access to basketball courts and tennis courts.

Indoor dining will remain closed.

Authorities inspected bars and restaurants this weekend to see how well they were complying with outdoor seating and social distancing. Of 1,000 businesses surveyed, 85% were in compliance, the mayor said.

10:08 a.m.: 100 homeless people in NYC die from coronavirus

There have now been 100 deaths attributed to the coronavirus among people in New York City experiencing homelessness, according to the city's Department of Social Services.

They are among the 1,293 homeless people in the city to be diagnosed with COVID-19.

8:50 am.: NBA star JJ Redick on the return of basketball

As the NBA gears up for its return, New Orleans Pelicans player JJ Redick calls it a "personal decision" whether to play or not, but that he felt a responsibility to his job, teammates and the league.

What so many Americans want is normalcy, Redick said, and bringing back sports is a "component of normalcy."

"We want to give the fans something to watch," he told "Good Morning America" on Monday.

The NBA plans to resume its season with 22 teams on July 30 at the Disney complex in Orlando, Florida.

"I don't think it's wrong to say we shouldn't play," Redick said, adding, "we're gonna try to play. We're trying to make the best of a bad situation."

"This is an unprecedented time," Redick said, as he commended the league and union leadership for what he called an "amazing job" creating "an environment where we can go play basketball and, as best we can, only worry about basketball."

"But that's obviously gonna be very difficult," he continued. "We're isolated and away from our families, there's social unrest, political unrest. ... We have to do our job and try to focus on playing basketball to the best we can, but we realize there's way more important things going on in our country right now."

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7:25 a.m.: Australia closes state border for first time in 100 years after COVID-19 surge

The border between Australia's two most populous states will close Tuesday for an indefinite period of time as authorities scramble to contain an outbreak of the coronavirus in Melbourne.

The closing of the border between the states of Victoria and New South Wales marks the first time it will be shut in 100 years. The last time movement was blocked between the two states was in 1919 during the Spanish flu pandemic.

The move is expected to deal a blow to Australia's economic recovery as it heads into its first recession in nearly three decades.

The number of COVID-19 cases in Melbourne has surged in recent days and has forced authorities to enact strict social-distancing orders in 30 suburbs, including putting nine public housing towers into complete lockdown.

There were 127 new COVID-19 infections announced overnight, the biggest one-day spike since the pandemic began. Two deaths were also reported taking the national total to 106 after no deaths were reported over the previous two weeks.

New South Wales Premier Gladys Berejiklian said there was no timetable for reopening the border which will be patrolled by the military to prevent illegal crossings.

"It is the smart call, the right call at this time, given the significant challenges we face in containing this virus," Victoria Premier Daniel Andrews told reporters in Melbourne.

Australia has had a total of just under 8,500 confirmed COVID-19 cases since the global pandemic began but the recent surge of an average of 109 cases per day in July compared with the average of just nine cases in the first week of June has raised alarm bells across the country.

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6:43 a.m.: NHL, NHLPA finalize protocols for season to resume in Edmonton and Toronto

The NHL and NHLPA have finalized the protocols for the season to resume this summer in Toronto and Edmonton, Alberta, NHL deputy commissioner Bill Daly told ESPN.

As of Sunday night, the sides still were finalizing the details of a memorandum of understanding for a collective bargaining agreement extension.

The Phase 3 (training camp) and Phase 4 (24-team tournament) return-to-play protocols will need to be approved by the NHLPA's executive committee, which is composed of one representative from each of the 31 teams. Once that is done, the entire package -- both the return-to-play protocol and the CBA extension -- will go to a full membership vote of all NHL players. The NHL's board of governors also must ratify the package.

The NHL is now targeting a July 13 start date for training camps, sources told ESPN. If all goes according to plan, teams would travel to the hub cities on July 25 or July 26, and games will begin by Aug. 1. The Eastern Conference teams will play in Toronto, and the Western Conference teams will be in Edmonton.

The 24-team tournament will conclude with a Stanley Cup Final in Edmonton, likely in early October.

The protocols include an agreement that no player will be penalized if he chooses to opt out, and he does not have to give a reason for wanting to opt out. Players have until 5 p.m. ET on Tuesday to notify their teams if they are opting out.

Family members will not be able to join players until the conference finals.

According to the document, "all individuals shall maintain physical distancing (a minimum of 6-foot distance) at all times throughout Phase 4, to the extent possible" -- which includes being on planes and buses, at restaurants and in any social circumstances. The league will provide face coverings, though individuals may bring their own, and they must be worn at all times in the secure zones. Players do not need to wear face coverings while exercising, and coaches do not need to wear them while on the bench.

If teams do not comply with the protocols, it could lead to "significant financial penalties" and potential loss of draft picks.

5:19 a.m.: Over two-thirds of Georgia Tech faculty protest plans to reopen

More than two-thirds of the Georgia Institute of Technology's academic faculty are protesting the school's plans to reopen this fall amid the coronavirus pandemic without making face masks mandatory.

An open letter, dated July 2, has garnered the signatures of more than 800 professors out of the roughly 1,100 faculty members at the public university in Atlanta. The letter voices concerns that the reopening plans "have been shaped based on guidance from outside the Institute, and with limited input from the faculty who are being asked to carry out these plans."

"We are alarmed to see the Board of Regents and the University System of Georgia mandating procedures that do not follow science-based evidence, increase the health risks to faculty, students, and staff, and interfere with the nimble decision-making necessary to prepare and respond to COVID-19 infection risk," the letter states.

The faculty are asking, among other things, that the school require face masks be worn everywhere on campus, provide large-scale COVID-19 testing, ensure timely contact tracing of new infections and make most classes take place remotely during the fall semester. The current reopening plans make masks mandatory for professors, while students are "strongly encouraged" to wear them.

ABC News has reached out to the Board of Regents and the University System of Georgia for comment.

The letter was first reported by Georgia Public Broadcasting.

3:30 a.m.: US reports over 49,000 new cases in a single day

More than 49,000 new cases of COVID-19 were identified in the United States on Sunday, according to a count kept by Johns Hopkins University.

The latest daily caseload is just under the country's record high of more than 54,000 new cases identified last Thursday.

The national total currently stands at 2,888,729 diagnosed cases with at least 129,947 deaths, according to Johns Hopkins. The cases include people from all 50 U.S. states, Washington, D.C., and other U.S. territories as well as repatriated citizens.

By May 20, all states had begun lifting stay-at-home orders and other restrictions put in place to curb the spread of the novel coronavirus. The day-to-day increase in cases then hovered around 20,000 for a couple of weeks before shooting back up and crossing 50,000 for the first time last week.

Nearly half of all 50 states have seen a rise in infections in recent weeks, with some -- including Arizona, California and Florida -- reporting daily records.

ABC News' Libby Cathey, Stephanie Ebbs, Matt Fuhrman, Joshua Hoyos, Will Gretsky, Aaron Katersky, Rachel Katz, Bonnie Mclean, Evan Mcmurry, J. Gabriel Ware, Scott Withers and Rosa Sanchez contributed to this report.