A 10-car train made a recent appearance on the Green Line, according to Matt Bassett, the chair of the Tri-State Oversight Committee.

On June 17, Bassett said a train left the Branch Avenue rail yard with two additional cars.

“This implies that the operator failed to follow the necessary rules for prepping and moving their train into service, and it is a safety concern,” he wrote. “If someone somehow got into one of the back cars, the doors would open onto the tracks and in range of the third rail.”

Dan Stessel, a Metro spokesman, said the employee was suspended because the incident was “an operating rule violation.”

Stessel said the situation was discovered before the train ever left the first station.

Follow me on twitter @postmetrogirl.