Transcript for Trump warns coronavirus crisis could stretch into summer
It's great to have you with us. It's been a remarkable thing we've all witnessed together, a reset of American life. Trying to get groceries with empty shelves, trying to find children child care. How will parents manage the weeks ahead without school, and the ongoing struggle for people who think they may have coronavirus. Are the hospitals ready? We'll get to it all tonight. More than 4,600 cases that we know of, and 82 deaths. President trump acknowleding that the virus is not under control. Saying it may take until July or August to in his words wash through the country. Saying not to go to restaurants and bars. 35 states closing schools for 36 million students. New York City sending more than 1 million students home. Late today, drastic steps in several hot spots. In San Francisco, 7 million ordered to shelter in place at home, for at least three weeks. Empty shelves in grocery stores. This line just before dawn this morning. And in so many stores, they're stripped clean. At airports over the weekend, we witnessed this, Americans returning home from overseas. Standing in lines, some for hours, at medical checkpoints. And the stock market, the emergency trigger kicking in today again, even after the fed took extraordinary action. Whit Johnson leads us off right here in New York City tonight. Reporter: Tonight, with daily life grinding to a halt across America, the white house announcing drastic steps. Part of a 15-day plan to slow the spread. We'd much rather be ahead of the curve than behind it. Reporter: President trump's coronavirus task force now urging people to avoid gatherings of ten or more people. Discretionary travel. Encouraging older people and those with underlying conditions to stay home. The administration also telling people not to visit nursing homes. And recommending bars and restaurants close in states with community spread. If everyone makes this change or these critical changes and sacrifices now, we will rally together as one nation and we will defeat the virus. But you're not saying it's under control, right? I am not referring to "It," meaning the -- The coronavirus. Yeah. If you're talking about the virus, no, that's not under control for any place in the world. Reporter: The president now warning the crisis could stretch deep into the summer. People are talking about July, August -- something like that. So it could be right in that period of time where I say it washes -- it washes through, other people don't like that term, but where it washes through. Reporter: But today, a major step toward a possible vaccine. The trial is taking place in Seattle. There will be two injections. One at zero day, first one. Then 28 days. There will be three separate doses. Reporter: Volunteer Jennifer haller getting the first injection in Seattle as part of that clinical trial. Everybody is feeling so helpless right now. I realized there was something I could do to help. Reporter: The vaccine still not expected to be available to the public for at least a year. Tonight with the cases across the country climbing, more than a dozen states already closing bars and restaurants, except for takeout and delivery. Including New York, Connecticut, and New Jersey, who will also shut gyms, movie theaters, casinos, starting tonight. This is a national problem. It cannot be done in a piecemeal method. Reporter: In the San Francisco bay area, a sweeping shelter in place order for nearly 7 million people. Residents told to only leave their homes for food, medicine, and exercise. California's governor is urging home isolation for all adults over the age of 65. The most important thing is to protect the most vulnerable. Reporter: At least 35 states closing public schools -- forcing more than 35 million kids to stay home. It creates a lot of hardship for people but it's the right choice. Reporter: In Boston, volunteers boxing up homework to deliver to students at home. And with so many American children without access to school meals, communities from Pennsylvania to Texas stepping up to make sure families have the supplies they need. Trying to stay positive in a bad situation. So, that's it. Reporter: Long lines at Costcos from Illinois to Los Angeles. And thousands of people are rushing to try to get into the Costco here in the city. Reporter: Lines snaking around the building before dawn. Stores running out of basic items like toilet paper and water. The stop and shop grocery chain announcing new early shopping hours for customers 60 and over. At U.S. Airports, chaos as Americans rush home. Passengers waiting hours, shoulder to shoulder for medical screenings. I definitely felt unsafe. If the government is telling me to stay in groups of less than 50 and keep social distancing, that was the opposite. Reporter: But departures areas around the country eerily empty. Look at this! There's just nobody here at the airport. Whit, the president and these new guidelines. Dr. Fauci saying this is guidance for the next 15 days, then they will reassess. And the president was asked if he was considering a nationwide quarantine. Reporter: He made clear at this point they are not looking at a quarantine. But they are looking at hot spots to see if additional restrictions are required. Thank you.
This transcript has been automatically generated and may not be 100% accurate.