DENVER — A social media video taken at Denver International Airport went viral this week, showing one of the airport's trains running with the doors still open. It happened on Tuesday, and the video ...

The Arterios were designed for driver-only operation, which unions argue will render train guards obsolete - Jas Lehal Media Assignments/PA A trade union row over who should close doors has delayed a ...

Officials said they are investigating what caused the door to open but have ruled out an issue with the train itself or a mechanical problem.

DENVER (KDVR) — Engineers are investigating what caused a safety feature to fail after a train between concourses at the Denver International Airport ran with doors open earlier this week. A train ran ...