Gary Hogan, who was 15 when he set off a bomb in 1970 at Dayton's department store in St. Paul, has died in Washington, D.C.

Hogan, who died May 24 at age 55, had changed his name to Kofi Y. Owusu while serving three years in juvenile prison. He then moved to Washington and lived a productive life.

The bomb went off in the women's restroom of the downtown Dayton's store in 1970. Mary Peek, who became a well-known political activist, was seriously injured in the blast. She died in 2005.

A second, much more powerful bomb with a faulty timing device was found nearby and didn't explode. Police theorized that the first bomb was meant to draw police and fire personnel to the area, where they'd be injured or killed by the second bomb.

A news account from that time said police found bombmaking instructions and a pamphlet on urban guerrilla warfare in Hogan's home. He was convicted of attempted first-degree murder and aggravated arson and sentenced to 20 years in prison. He served just more than three years in the St. Cloud Reformatory.

A memorial service was held Aug. 14 in St. Paul, where he was born. Over the years, he worked as a journalist and a civil rights advocate and served in the Peace Corps.

The bombing came at a time of racial unrest across the country and growing opposition to the Vietnam War. There were numerous bomb threats and evacuations in the Twin Cities at the time.

Survivors include a son and a brother.