EBENSBURG — A man who blew up himself with a device in his truck that leveled an acquaintance’s rural Western Pennsylvania home tried to commit suicide last summer with a 1,600-pound fuel bomb similar to one used to blow up the Oklahoma City federal building in 1995, a prosecutor said Wednesday.

Cambria County District Attorney Kelly Callihan said her office asked a judge to revoke the bond of Bradley Kollar, 40, last June after learning of the suicide attempt, which he discussed with his ex-girlfriend in a call that was recorded because she was jailed. But Kollar’s attorney objected and the judge agreed to let him remain free on bond while illegal possession of chemicals and stolen vehicle charges against him wound their way through the courts, Callihan said.

Kollar told the woman he was stressed about those legal troubles and lighted the bomb’s fuse three times, only to have it fail.

“Three times. When I talk about it, it makes my hair stand up,” Kollar said. A transcript of the bomb hearing shows the judge refused to revoke his bond because he was never charged with making it and didn’t threaten to use it on anyone else.

Kollar of Hastings was set to be sentenced Tuesday on those charges when he instead drove to the Clearfield Township residence where the explosion occurred, injuring the homeowner, William Shaner, 44, and one of his teenage sons, state police Trooper John Matchik said.

State police and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives continued to comb the rubble Wednesday for clues.

“At this time, we cannot confirm any specific motive or possible retaliation,” Matchik said, though he and Callihan acknowledged that revenge is one possibility. He said the blast is being treated as an “attempted criminal homicide.”

Matchik said that Shaner was an acquaintance of Kollar’s and that police have learned Kollar phoned Shaner moments before the blast.