Hourslong airport waits and crowds overflowing the terminal and spilling out onto the sidewalk greeted travelers at Hartsfield-Jackson Atlanta International Airport early Monday morning, as a partial government shutdown leaves airport security checkpoints understaffed.

It’s the first day Immigration and Customs Enforcement officers were deployed to assist in managing airport security at cities across the country, including at the Atlanta airport. It appeared officers mainly were observing operations and long lines persisted, at least in the early hours of the day.

As early as 5:30 a.m., an airport employee estimated it could take travelers at least four hours to get through Transportation Security Administration checkpoints.

Some travelers were told wait times could be even longer — as long as five hours.

Later in the morning the lines alleviated some, but airport officials have still urged travelers to get to the airport at least four hours early.

Monday mornings are a typically busy travel period at the world’s busiest airport, with the terminal filled with people traveling for work. But it’s also the spring break travel period.

The U.S. Department of Homeland Security said more than 400 TSA officers have quit their jobs across the country “because they are not able to afford gas, childcare, food or rent.” Others are calling out of work as they are forced to find other ways to earn money to pay their bills.

In Atlanta, 41.5% of TSA workers called out of work on Sunday, according to DHS.

Other airports also had high callout rates, including New Orleans’ airport with a 42.3% callout rate, Houston’s Bush airport at 39%, Baltimore/Washington International at 38% and New York’s John F. Kennedy International at 37.4%.

Some travelers in the early morning rush were wearing casual clothes, the telltale signs of a spring break vacation about to begin; others sported business attire.

Travel is Ben Amerson’s specialty. He runs a travel agency in the city of Forsyth that specializes in group trips, primarily for students.

Getting caught in the mayhem of a partial government shutdown feels especially ironic for someone who makes his living keeping other people’s travel running smoothly. He was flying out of Hartsfield-Jackson on Monday morning to lead a trip in New York City.

In his decades spent traveling, he said he’s never seen security lines this bad.

He’s having to follow the advice he’d give to his clients if they were also stuck in long lines.

“Be patient. Expect it. Try to prepare, plan,” Amerson said. “Don’t drink any water because you can’t get out of line to go to the bathroom.”

Air travel across the U.S. was also disrupted by a fatal collision late Sunday night of an Air Canada Express regional plane with a fire truck at New York’s LaGuardia Airport. The incident killed the pilot and co-pilot of the plane and led to numerous other injuries, according to The Associated Press. LaGuardia is also closed to flights until at least 2 p.m.

Delta is the largest carrier at LaGuardia, where it has a hub, and its flights were significantly disrupted by the airport’s closure.

According to FlightAware.com, more than 590 flights have been canceled at LaGuardia so far today, including more than half of Delta and its regional partners’ schedules.

Federal ICE agents assist TSA operations while travelers line up for security at Hartsfield-Jackson Atlanta International Airport on Monday. ICE agents will not carry out immigration enforcement during this deployment, according to Atlanta Mayor Andre Dickens. (Miguel Martinez/AJC)

Over the weekend, the Trump administration said ICE officers would assist in managing airport security at cities across the country, and Atlanta Mayor Andre Dickens confirmed Hartsfield-Jackson would be one of those airports.

An Atlanta Journal-Constitution reporter observed at least five ICE officers at the north side of the main domestic terminal early Monday morning.

Homeland Security Investigations agents were also present. It’s unclear what impact ICE’s presence was having. Officers were not staffing sensitive checkpoint equipment and most officers seen by AJC reporters at the scene appeared to be observing travelers in lines and did not appear to be approaching anyone.

“Our administration will continue to monitor the situation closely and remain in communication with the public and travelers as these federal actions develop,” Dickens said in his statement.

Hartsfield-Jackson said it has bolstered its staffing at the airport with personnel to help with crowd management, way-finding and navigating the airport, but Hartsfield-Jackson does not have control direct control over the security checkpoints. That’s the purview of TSA, which is suffering from high rates of call-outs as workers have not been paid for weeks.

The partial government shutdown, which started last month, affects DHS, of which TSA is a part. Democrats refused to fully fund DHS until the Trump administration agreed to changes to immigration enforcement practices after the fatal shootings of two U.S. citizens by ICE officers in Minnesota.

Democrats have proposed funding TSA and other elements of DHS until the impasse can be resolved.

Senate Majority Leader John Thune made a proposal to President Donald Trump on Sunday to fund DHS without ICE in order to end the impasse, Punchbowl News reported.

Punchbowl News said Thune told Trump that Senate Republicans would support funding all of DHS except ICE, but Trump said no.

Trump posted on Truth Social on Sunday evening he would not back a deal unless it includes the Republican elections bill, the SAVE America Act. “In other words, lump everything together as one, and VOTE!!!” he posted.