(Nikki Kahn/The Washington Post)

Multiple human errors led to a red-light running incident near the Smithsonian station last week that left two trains facing each other on the same track, Metro officials said Wednesday.

“There’s a primary, secondary and tertiary failure, which concerns me,” said Rob Troup, Metro’s operations chief.

Those failures included an operator’s misunderstanding of an instruction from a rail operations controller; the controller’s failure to notice when the operator repeated back his misunderstanding; and the operator’s subsequent running of the red signal, a basic violation of a critical safety rule, officials said.

The Federal Transit Administration has said Metro has a serious and persistent problem with red-signal running, and this most recent incident remains under investigation by the FTA.

In last week’s incident, an operator learned of a switch problem beyond the McPherson Square station. He was told to offload his passengers and then reverse course on the same set of tracks, officials said. He was instructed to travel, following special, low-speed safety rules, back to the Federal Triangle station, Metro officials said.

The operator then repeated back an incorrect set of directions to his controller, saying that he would take the train back to the Smithsonian station (which is beyond Federal Triangle,) officials said.

The controller did not correct the operator, and did not stop him, Metro officials said.

The operator then headed out, moving at 10 mph, continued past Federal Triangle and continued toward the Smithsonian station, officials said.

As he moved closer to the station, the operator ran through a red light, damaged a switch and, upon seeing a revenue train parked at the station with its doors open, slowed further and stopped his train, officials said.

It came to rest 189 feet from the other train, which had passengers aboard.

Metro officials declined to describe what they have learned about the nature of the mistakes and misunderstandings, other than to say they have found no evidence of cellphone use or other prohibited behavior.

Metro General Manager Paul J. Wiedefeld said an immediate new safety procedure was put in place:  Now, a supervisor at the operations control center comes to stand behind, and act as a literal backup for, controllers who are orchestrating an unusual train move such as reversing a train, Wiedefeld said.

Officials said the investigation is ongoing.