Metro said one of its mechanics was struck by a train at its Shady Grove rail yard Tuesday after he stepped in front of it.

The man is listed in critical condition.

The incident happened just before 1 p.m. when a four-car train in the car wash area struck the man. He was rescued from under the first car of the train, according to Metro officials.

According to a news release from Metro, “an eyewitness reported that the employee stepped into the path of the lead railcar.”

Representatives from the National Transportation Safety Board, the Tri-State Oversight Committee and Federal Transit Administration responded to the scene.

“We have no reason to believe that this was intentional,” said Dan Stessel, Metro’s chief spokesman.

Stessel said the accident is still being investigated. Metro has not released the man’s name. Jackie Jeter, president of Metro’s biggest union — Local 689 — said Tuesday that she had been told that the man had “lost part of his leg.”

Metro has had incidents of workers dying after being hit. In 2010, two track workers were struck and killed by equipment near the Rockville station. In 2009, two workers were fatally struck: one near the Dunn Loring stop, the other at Reagan National Airport.

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