PITTSBURGH (KDKA) – Millions across the United States are in mourning following the death of Congressman John Lewis.

That includes both Pennsylvania senators Pat Toomey and Bob Casey.

“Deeply saddened by the news of Congressman John Lewis’s passing—an American hero and relentless champion for justice with unwavering optimism for our Nation,” Senator Casey tweeted. “The world is a little darker this morning without his light.”

“A civil rights leader and dedicated public servant who successfully led numerous fights in the name of equality and against racism and discrimination,” Senator Toomey also tweeted.

Along with both senators, U.S. Congressman Mike Kelly of Butler also reflected on the life of Rep. Lewis.

“I think too often, we think, ‘oh, they’re going to be here forever,'” said Kelly. “The whole country now is stopping and looking back on a life well-lived, a life of service, it gives you time to reflect and say ‘wow, that’s what John Lewis did? What have I done and what can I do to try and measure up, in some way, to the same mission he was on?'”

John Lewis was 80-years-old.