Bob Urman was sitting in a recliner in his apartment in the heart of St. Paul, about to watch a Minnesota Twins game on TV, when he heard a loud “Boom!” and his window shattered.

Urman thought it sounded like a shotgun blast. Then he looked closer.

A small steel object had smashed a hole through his window, busted the venetian blinds, dented the back of his TV and left a burn mark on the carpet. He called the apartment’s caretaker, who was away at work. Then he called police.

What the object is remains a mystery.

Urman has been to war, but he says that in his 80 years he’s never experienced anything like what happened Wednesday.

“I said to the officers, ‘I don’t believe in UFOs. Do you guys?,’ ” Urman said Thursday. “They kind of smiled and said, ‘Sir, we don’t know what it is.’ ”

The officers told Urman, who lives on Snelling Avenue near University Avenue, that the object appeared to have hit his window at high speed and to have come from above. It was still warm when an officer handled it about 45 minutes later, Urman said. Police speculated that it could have been a piece that fell off an airplane, Urman said.

But police officers brought the object to the airport, where police had some airline mechanics look at it. They didn’t think it looked like a plane part, said Patrick Hogan, Metropolitan Airports Commission spokesman. Their best guess: It was an automobile wheel hub.

Urman doesn’t know about that. He lives on the third floor, and his window faces an alley.

“It doesn’t resemble anything from a car to me,” he said. “If it was from a car, how would it get up here on the third floor?”

The object was black and silver, smaller than a baseball and shaped like a mushroom, Urman said. It seemed to be solid steel, he said.

“I’ve never experienced anything like this in my life,” said Urman, who is retired from working on a trucking dock.

What about when he was a U.S. Marine, driving a tank during the Korean War?

“Well, you expect that because you’re in a war,” he said. “Here in a peaceful town, you’re just switching over to watch a ballgame and something like that happens. It jolts the hell out of you.”

Mara H. Gottfried can be reached at 651-228-5262. Follow her at twitter.com/MaraGottfried.