Metro’s largest union of employees says rail mechanics have stopped working on the transit system’s newest cars after a worker was electrically shocked and hospitalized Sunday.

“He was extremely lucky,” said mechanic Zuri Tesheira, who spoke to WUSA9 on behalf of ATU Local 689. Union members say they have found 7000-series railcars are repeatedly plagued by failing grounding brushes, which can enable any part of the car to become electrified.

ATU 689 President Jackie Jeter says the union and WMATA management agreed to stop work on the cars, known as a safety stand-down, to further investigate problems and appease union concerns.

“It hasn't been brought to the forefront for the public to actually decide if these trains are what's built for our system,” said Tesheira.

WMATA would not comment directly on the safety stand-down, but released a statement Wednesday saying it has called for new checks of problem parts.

“While the investigation is ongoing, Metro is not aware of other shock-related incidents with similar circumstances,” said WMATA spokesman Dan Stessel.

Workers insist this has happened four times. The fear next time, the result could be deadly.

“If these ground brushes are not in place then getting shocked is the least of your worries,” said Tesheira.

Thursday, Metro voluntarily initiated a “safety stand-down” that resulted in the temporary suspension of mechanical inspections of 7000-series railcars. They say customers to expect fewer trains, possible crowding as safety concern is reviewed.