Travelers confronted major disruptions at airports in the New York City area on Monday as a security staffing shortage from the partial federal government shutdown combined with the closure of LaGuardia after a fatal runway crash.

Videos posted to social media showed massive crowds waiting to go through security at JFK and Newark airports, with some travelers reporting they missed their flights after hours on line. The delays come as many Transportation Security Administration workers are calling out amid the ongoing partial shutdown of the U.S. Department of Homeland Security, which houses TSA, and as President Donald Trump said he is sending immigration agents to airports across the country to help with security backlogs.

The late-Sunday crash at LaGuardia between an Air Canada plane and one of the airport’s emergency response vehicles only made a strained travel situation worse for local fliers. Port Authority officials said two pilots were killed in the collision and dozens of other passengers and crew members were sent to the hospital. Some of the crew and passengers had serious injuries, officials said.

LaGuardia was expected to remain closed at least until 2 p.m. Monday as the investigation into the crash continued. By late morning, a handful of flights at the airport were being scheduled for after 2 p.m. Monday, and more passengers were entering Terminal B to go to their gates.

As of late Monday morning, global flight tracker FlightAware showed nearly 600 flights in and out of LaGuardia canceled on Monday, along with almost 300 flight delays at Newark and JFK.

Anticipating a long wait, Alexandra Allen said she arrived at JFK’s Terminal 4 at 8 a.m. for her 1 p.m. flight to Miami. But instead of spending hours on line, she said she breezed right through security.

“When I showed up to check my bag, there was barely a line,” she said, adding that she panicked after getting notified that her flight, which was supposed to leave from LaGuardia, had been moved to JFK due to the crash. She said a JFK staff member told her she’d gotten lucky, because the airport had been much more crowded earlier in the morning.

Allen said she was traveling with a pilot, who explained that boarding and takeoff at JFK often happens in waves, so it’s even harder to anticipate how many people might be at the airport at any given time.

“I’m just going to hang out in the lounge,” she said in a phone interview.

TikTok and other social media platforms have been flooded with videos from airport travelers in the last several weeks, trying to help others know what to expect and how early to arrive. Those videos continued to capture frustration early Monday — both from those who had experienced long waits and those who showed up early but did not meet significant delays.

Newark Airport also experienced a ground stop Monday morning after its air traffic control tower was temporarily evacuated around 7:30 a.m. because of a burning smell coming from an elevator, according to the Federal Aviation Administration. Personnel returned to the tower about an hour later, the agency said, and operations returned to normal.

Gothamist observed several federal Homeland Security officers and U.S. Immigration and Customs Enforcement agents patrolling LaGuardia terminals on Monday morning in their agency gear. The Department of Homeland Security did not immediately respond to a request for comment about its deployments to New York metro airports.

This is a developing story and may be updated.