Elijah Cummings, chairman of the House Oversight Committee, a pivotal figure at the center of the impeachment proceedings of President Trump has died, at the age of 68.

The African American lawmaker, who often clashed with the president, died “due to complications concerning longstanding health challenges,” his office said on Thursday, Oct. 17. He was admitted to Gilchrist Hospice Care, a Johns Hopkins affiliate where he died early on Thursday, according to a statement from his office.

Cummings, who was a leading voice in the Congressional Black Caucus, had been suffering from ill health for the past few years and often used a motorized cart or a walker.

The New York Times reported that Cummings had heart surgery in 2017 and had a bacterial infection in his knee.

House Oversight and Reform Committee Chair Elijah Cummings (D-Md.), on April 2, 2019. (J. Scott Applewhite/AP Photo)

Tributes have poured in from lawmakers.

“This is a terrible tragedy,” tweeted Howard Dean, the former Democratic governor of Vermont. “Elijah is one of the most honest, thoughtful, decent people I ever met in politics. His moral compass was unfailing throughout his life in and out of politics. My deepest thanks to Elijah’s family for lending him to our country for all these years.”

“My heart is broken, as I weep personally and for his family and community,” Florida Democratic Rep. Debbie Wasserman Schultz said, reported Fox News. “Elijah Cummings’s unmatched integrity and leadership leaves a remarkable legacy.”

New York Rep. Carolyn Maloney is next in line to take over the gavel for the committee.