Travelers trying to return home on the last flights into the United States ahead of coronavirus-related travel shutdowns were forced to wait hours in line for medical screenings, customs checks, and immigration processing Saturday night, after American authorities failed to adequately anticipate and prepare for the travel spike.

The United States announced Friday that travelers coming in from Europe on Friday, Saturday, and Sunday — the last days before a coronavirus-related “travel shutdown” goes into full effect — would be routed through 13 international airports, where the Transportation Safety Administration and U.S. Customs and Border Protection had both the facilities to process large numbers of travelers, and the ability to quarantine any travelers suspected of carrying the dreaded coronavirus.

That decision left customs officials at airports like Dallas Fort-Worth (DFW) and Chicago’s O’Hare International (ORD) overwhelmed, the Associated Press reports, and left travelers stranded for up to 8 hours at a time waiting for basic screening.

The system at DFW was “atrocious, no semblance of a line beyond the barriers and no officials or staff around to direct,” one traveler told the AP.

“Everybody was nervous about it,” an O’Hare traveler said of the staff processing newly arrived passengers. “Everyone working there was confused and frustrated, and [their] hands were tied, too.”

“People arriving in the US shared accounts of chaos and confusion as they waited to go through customs at airports including Chicago’s O’Hare International Airport and Dallas/Fort Worth International Airport,” Buzzfeed News added Saturday. “Photos showed winding lines and shoulder-to-shoulder crowds, with people reporting wait times from 5 to 7 hours long.”

“This is the scene at O’Hare airport,” one social media user tweeted above a photo of incoming passengers packed into an atrium. “The traveler who took the photo said it’s a 6-hour wait for bags then on to customs for 2-4 more of waiting in shoulder-to-shoulder crowds. Police are handing out water and disinfectant wipes.”

This is the scene at O’Hare airport. The traveler who took the photo said it’s a 6-hour wait for bags then on to customs for 2-4 more of waiting in shoulder-to-shoulder crowds. Police are handing out water and disinfectant wipes. @fly2ohare #ord #coronavirus #COVID19 pic.twitter.com/UTx9E0nj1s — Brooke Geiger McDonald (@BrookeGMcDonald) March 15, 2020

Passengers were concerned, too, that they were being shuttled through hallways and holding areas where people were packed shoulder-to-shoulder — much closer than the CDC’s heavily recommended “social distancing” policies should allow. At DFW, passengers complained that there were no measures being taken to ensure sanitary conditions — and no hand sanitizer available to those who waited hours just inches from other people who had not been screened for coronavirus.

States, airports, and the Department of Homeland Security disagreed on which entity was at fault for the issue. O’Hare Airport and Illinois governor J.B. Pritzker laid the blame squarely at the feet of the Trump administration and urged Federal authorities “to increase staffing to meet demand.”

Acting Department of Homeland Security Secretary Chad Wolf said Federal agencies are working to streamline the process of screening incoming travelers, but that each person must undergo a 60-second health check.

“Right now we are working to add additional screening capacity and working with the airlines to expedite the process,” Wolf tweeted. “I understand this is very stressful. In these unprecedented times, we ask for your patience.”

On Saturday, the process was moving faster, but fewer flights were coming in. Sunday, the final day that U.S. citizens and greencard holders can re-enter the United States before a complete travel ban takes effect, is expected to be very busy.