The union said Ricardo Louis, 44, collapsed around 3:10 a.m. while working on an L train at the Morgan Avenue station. Coworkers attempted to revive Louis and called 911. Emergency medical services transported him to Woodhull Hospital, but efforts to save him were unsuccessful, the union said.

An MTA worker died after going into cardiac arrest on an L train in Brooklyn, sources said. The 44-year-old subway track worker, identified by the Transport Workers Union as Ricardo Louis, collapsed while performing his job duties at the Morgan Avenue stop,

An MTA trackworker died while working on a Brooklyn L train Wednesday morning, the Transit Workers Union Local 100 reported.