(CBS)

Representative Elijah Cummings, of Baltimore, died early Thursday at the age of 68, his office said.

Cummings passed away at Johns Hopkins Hospital at 2:45 a.m. from “complications concerning longstanding health challenges,” his office said.

He hadn’t returned to work after having a medical procedure that he said would only keep him away for about a week, The Baltimore Sun pointed out.

The House Oversight and Reform Committee chairman, a Democrat and 23-year House veteran, was a key figure in the impeachment inquiry into President Trump and a recent target of intense criticism from the president.

Cummings missed two roll call votes Thursday, the first day back following a two-week House recess. He previously released a statement saying he’d be back by the time the session resumed. He hadn’t taken part in a roll call vote since Sept. 11.

The procedure already caused Cummings to miss a September hearing on Washington, D.C., statehood. The statement didn’t detail the procedure.

He previously was treated for heart and knee issues.