Coronavirus updates: State declares public health emergency over case 'surge'

In North Carolina, larger outdoor event venues can reopen at 7% capacity on Oct. 2., Gov. Roy Cooper said Tuesday.

The state's positive test percentage has been dropping and is now between 5 and 6%, state officials said.

Meanwhile, North Carolina's Department of Health and Human Services announced a new contact tracing app called "SlowCOVIDNC."

The app will alert people "when they may have been exposed to someone who has tested positive for COVID-19," the Department of Health and Human Services said Tuesday. "It is completely anonymous and does not collect, store or share personal information or location data."

Wisconsin Gov. Tony Evers declared a public health emergency on Tuesday due to a "recent surge in cases among young people."

Eighteen to 24 year olds have a COVID-19 case rate five times higher than any other age group, according to the governor.

"We are seeing an alarming increase in cases across our state, especially on campus," Evers said in a statement. "We need folks to start taking this seriously, and young people especially—please stay home as much as you are able, skip heading to the bars, and wear a mask whenever you go out."

Wisconsin is "experiencing unprecedented, near-exponential growth of the COVID-19 pandemic," the governor's office said.

On Aug. 31, the number of new daily cases reported in the state was at 678. On Monday, the number of daily cases reported was 1,791.

Evers on Tuesday also issued a new face covering order requiring residents ages 5 and older to wear a mask indoors.

The novel coronavirus has now killed 200,000 people in the United States, just eight months after the nation's first confirmed case.

The U.S. death toll from COVID-19 currently stands at 200,005, according to a real-time count kept by Johns Hopkins University.

The first case of the novel coronavirus in the United States was reported in a patient in Washington state on Jan. 20, according to the U.S. Centers for Disease Control and Prevention.

Four months later, on May 27, the U.S. death toll reached 100,000.

The novel coronavirus has now killed nearly twice as many Americans as the 116,516 who died in World War I, the third-deadliest conflict in the nation's history. More than 400,000 Americans died in World War II, while an estimated 655,000 died in the Civil War.

See this additional ABC News coverage marking the grim milestone:

200,000 Americans have died from coronavirus: A look at that grim milestone in context

As US hits 200,000 COVID-19 deaths, experts warn of growing mental health crisis

We've hit 200,000 COVID-19 deaths in 6 months. What will the next 6 months look like?

200,000 American lives lost from COVID-19: Here's what we've learned

WHO on a coronavirus second wave, lockdowns and how the world responded to the pandemic

200,000 dead: Federal response marked by chaotic messaging, unwarranted optimism

ABC News' Marc Nathanson contributed to this report.

An ABC News analysis of COVID-19 trends across all 50 U.S. states as well as Washington, D.C. and Puerto Rico found there were increases in confirmed cases over the past two weeks in 33 states, the nation's capital and the U.S. island territory in the Caribbean.

The analysis also found increases in the daily positivity rate of COVID-19 tests in 16 states and Washington, D.C., increases in COVID-19 hospitalizations in 17 states as well as in D.C. and Puerto Rico, and increases in daily COVID-19 death tolls in 15 states as well as in Puerto Rico.

The trends were all analyzed from data collected and published by the COVID Tracking Project over the past two weeks, using the linear regression trend line of the seven-day moving average.

The nationwide rise in COVID-19 cases may be correlated to several factors. Although the increase may be partially related to Labor Day festivities, it may also be tied to the virus spreading to communities from outbreaks on college campuses.

Moreover, the rise in new cases may be related to increasing mobility across states and communities. Several states, such as Idaho, North Dakota, South Dakota, Wisconsin and Utah, have seen a rise in mobility, according to a tracking tool created by Apple.

ABC News' Benjamin Bell, Brian Hartman, Soorin Kim and Arielle Mitropolous contributed to this report.