The Massachusetts senator and former presidential candidate Elizabeth Warren made public the news on Thursday that one of her brothers died of coronavirus earlier this week.

Warren made the announcement on Twitter, saying: “My oldest brother, Don Reed, died from coronavirus on Tuesday evening. He joined the Air Force at 19 and spent his career in the military, including five and a half years off and on in combat in Vietnam. He was charming and funny, a natural leader.”

She posted family pictures and a shot of him serving in the air force. He died in Oklahoma, where he lived, as do the senator’s other two brothers.

Warren, 70, was born in Oklahoma City, Oklahoma.

What made him extra special was his smile—quick and crooked, it always seemed to generate its own light, one that lit up everyone around him. pic.twitter.com/SFMOaBVCN3 — Elizabeth Warren (@ewarren) April 23, 2020

Donald Reed Herring was a Vietnam war veteran.

I’m grateful to the nurses and frontline staff who took care of him, but it’s hard to know that there was no family to hold his hand or to say “I love you” one more time—and no funeral for those of us who loved him to hold each other close. I'll miss you dearly my brother. pic.twitter.com/oOG6HArEL6 — Elizabeth Warren (@ewarren) April 23, 2020

Warren often mentioned his military service on the campaign trail.

Warren had not previously disclosed her brother had tested positive for the virus. According to the Boston Globe, he was hospitalized for pneumonia in February and then moved to a rehabilitation center, which had seen other cases of coronavirus. He was later brought to the intensive care unit of a nearby hospital, where he died.

The Globe reported that Herring was born in 1933 and attended the University of Oklahoma, but did not graduate, before enlisting in the air force, where he flew B-47 and B-52 bombers. He flew 288 combat missions in Vietnam, eventually becoming a B-52 squadron pilot and a squadron aircraft commander. He earned numerous decorations before retiring in 1973 as a lieutenant colonel and starting an auto-detailing business.

Warren dropped out of the presidential race in March and endorsed the presumptive Democratic nominee, Joe Biden, earlier this month.