DENVER — RTD is apologizing for stranding hundreds of passengers for hours on the A Line last Friday, but they're defending the decision to keep passengers on board, rather than allowing them to walk to safety.

The "Train to the Plane" was stuck for hours Friday evening near 61st and Pena.

In a statement Monday, RTD wrote:

“We sincerely apologize for the delays our passengers experienced. This clearly did not meet RTD’s expectations or standards. RTD and our contractor Denver Transit Operators are conducting a complete review of the incident to determine what occurred, how responses were made and how this may be prevented and properly handled moving forward.”

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RTD is reviewing what went wrong, including examining the decision to send a second train loaded with passengers to hook up with the first disabled train. That second train also hit a damaged overhead wire component, RTD said.

Passengers were not allowed to walk down the track, as we saw when the train was disabled in 2016, because portions of the system still had power this time, meaning it would have been unsafe. Spokesperson Scott Reed also told 9NEWS that walking on a trackway is a violation of the law.

RTD says typical procedure is to use an empty train for a rescue.

Stranded passengers complained to us via Twitter that they weren't getting clear communication from RTD, and the agency told us today they heard the same.

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RTD plans a review of the incident with its private partner on the train to the plane this week.

There were 115 passengers on one train, and 119 on the other. As reported Friday, RTD will not issue refunds for missed flights due to the delay.

“As with any service provider to and from Denver International Airport, including taxis, private shuttles, limos, Uber or Lyft, we are not able to provide refunds for air travel.”