ST. LOUIS—A St. Louis Lambert record of 25,913 passengers were screened by Transportation Security Administration authorities Sunday, a day marked by a crush of departing convention-goers who helped create long lines here.

Sunday was departure day for thousands of delegates leaving the Seventh-day Adventists’ General Conference, which was held at the America's Center complex downtown. Many of those delegates arrived early for flights scheduled later in the day, needed to check bags and weren’t set up with programs like TSA Pre-check or CLEAR that are supposed to ease airport security screening, according to airport officials. 

One St. Louis man not connected to the convention travel arrived just before 4 a.m. for a 6:10 flight, and found lines out the door with people holding tickets for flights that weren’t scheduled to leave until 11 a.m. or noon.

That man said he missed three flights because of the delay and ultimately drove to his destination.

A TSA spokesperson said all checkpoint lanes were open and that the agency was fully staffed for the higher volumes. An airport spokesperson said airline ticket counters and TSA were overwhelmed. 

Monday morning, airport officials said was still busy but that lines were moving. 

A spokesperson for the Seventh-day Adventists' General Conference did not immediately respond to a request for comment Monday.