A software coding error led a train between Denver International Airport’s main terminal and concourses to abruptly slow in March, as dozens more were evaluated for injury, according to the National Transportation Safety Board.
The NTSB, in a report released last year, said the error allowed an incorrect speed code to be sent to the train while it traversed a track crossover, causing a rapid acceleration to 22 mph. People were hurt when the train slowed to 8 mph.
Heath Montgomery, an airport spokesman, said the NTSB’s findings corroborate what airport officials believed caused the jolt.
“That issue was corrected very quickly after it happened,” he said Monday.
The incident happened about 2 a.m. on March 19 as the Bombardier train carrying 47 people was heading back to the airport’s main terminal.
Paramedics arrived on the scene and evaluated more than half of the passengers. Three of the passengers were taken by ambulance to University Hospital, and a fourth — a child — was taken to a hospital in a private vehicle.
“On that day, train 425 had previously completed four routes without any problems,” the NTSB said in its report, released in September but reviewed by The Denver Post on Monday.
At the time of the incident, Bombardier had a contract with the airport to upgrade the train’s signaling system.
Bombardier has since changed the software that contained the coding error, according to the NTSB.
