Penn State graduate and noted labor leader Richard Trumka unexpectedly died Thursday, according to multiple outlets.

Trumka, 72, served as president of the American Federation of Labor and Congress of Industrial Organizations (AFL–CIO) since 2009. He also closely worked with Democratic leaders and advocated for working Americans.

President Joe Biden said Trumka died of a heart attack while on a camping trip with family, according to NPR.

“He wasn’t just a great labor leader, he was a friend,” Biden said. “He was someone I could confide in. You knew whatever he said he’d do, he would do.”

The AFL-CIO is the largest federation of unions in the United States, and it represents more than 12 million workers, both active and retired. Before serving as president, Trumka was secretary-treasurer of the organization for more than a decade.

The federation’s current secretary-treasurer, Liz Shuler, said the AFL-CIO will continue fighting for workers in his memory.

Pennsylvania Governor Tom Wolf also released a statement following Trumka’s death.

“I extend my deepest condolences to the Trumka family. Our commonwealth and our nation have lost a good man and a great leader, and we grieve his loss with you,” Wolf said in a statement. “Rich came from a coal mining family here in Pennsylvania. He knew the value — and the cost — of hard work. In his life and career, he was an indefatigable advocate for American workers. As the head of one of our nation’s leading labor organizations, Rich was a strong supporter of the rights of workers, and a proponent of laws and policies that safeguard those rights. Rich stood up for the working-class people who built our nation, and for the democracy that keeps our nation strong. He will be missed.”

Trumka grew up in Nemacolin, a coal-mining town located in southwestern Pennsylvania. When he was 33, he was elected the youngest president of the United Mine Workers of America. T

Trumka graduated from Penn State in 1971.