A technical issue with the trains that serve the concourses and terminal caused slower Travel times and led to extremely long lines at the airport.

Hundreds of people waited to get through security and onto the trains, which were run manually by engineers as the situation was being worked on, airport officials said.

Security screening was moved to the A Bridge, and the north and south lines were closed while the issue was being worked on.

Meanwhile, a pedestrian was brushed by an RTD A Line train about 7:30 a.m., delaying service between the airport and Union Station for more than an hour.

Airport officials are expecting 178,000 passengers on Wednesday, enough to fill Sports Authority Field at Mile High more than twice.