01/23/2012 03:33 pm ET

Ozone Park Explosion Victim May Have Been Making Bombs, Cops Say

By Murray Weiss, Trevor Kapp and Jon Schuppe

OZONE PARK -- A man apparently making low-grade pipe bombs with powder from fireworks blew himself up inside his Ozone Park home Monday morning, sources said.

The man, 50, ignited the blast on 111th Avenue just before 9:30 a.m. and the explosion ripped apart his stomach, a source said. He was dead by the time paremedics arrived.

Investigators are looking into whether he was building bombs as part of a dispute with a former employer, a construction company. A police source described him as an "emotionally disturbed person."

A neighbor, Frank Kleineisel, said the man had recently suspected someone of breaking into the house, which he shared with his father. So he nailed the windows shut and installed cameras inside and outside the place.

"He thought someone from his job was trying to get him," Kleineisel, 42, said.

Kleineisel said he visited his neighbor at his home Sunday night, and found him "acting strange."

"He was a little uptight. He was depressed. But he wasn't violent. He never messed with anybody," Kleineisel said.

In addition to construction work, he had done body work on cars and had worked in a graveyard, Kleineisel said.

The man was not married and did not have any children, Kleineisel said.

"He always told me, 'Frank, if anything happens to me take care of my dad,'" Kleineisel added. "He was a good dude."

The man was last seen with a sparkler or something "sparkling" in his hand just before the explosion, a source said.

William Foley said he heard the blast from his home a few blocks away.

"I heard a loud bang, a pop," Foley, 28, said.

At first he thought it was gunshots. When he made his way toward the house, he saw a group of bomb-squad investigators outside. Foley asked if there had been a shooting.

"The bomb squad guy said, 'No, it's a bomb, get out of here,'" Foley said.

When police arrived, they were delayed by "a vicious dog in a bathroom," the source said.