The blast that killed a West Chester Twp. teen Wednesday afternoon came from a pipe filled with gunpowder, according to police.

Shrapnel from the blast struck Daniel Ferraro, 19, in the face. He was nearly 110 feet away at the time, said Sgt. Steve Oakes of the West Chester Police Department.

"We don't know if it was a piece of the bomb or a piece of the fort. That hasn't been determined yet," Oakes said.

Following a autopsy Thursday morning, the Butler County Coroner's Office confirmed Farraro died of a head injury, but further testing is needed to determine what caused the fatal blow.

"We may never know," said Andy Willis, coroner's investigator.

Police had previously responded to Ferraro's home on Apache Way on June 26, 2007, for reports of juveniles lighting aerosol cans but no arrests were made, Oakes said.

Neighbors said they could hear and feel Wednesday's deadly explosion.

"It was very loud. It shook the house," said Gary Hoff, who lives more than 100 yards away from 6747 Apache Way, where Ferraro lived and was killed in the backyard explosion.

One neighbor told police they heard blasts coming from the area maybe one or two times a week, Oakes said.

Capt. Joel Herzog of the West Chester Police Department said Ferraro and a group of teenagers were attempting to blow up a wooden fort around 2 p.m. Wednesday in the backyard of the home.

Police have charged Robert Moser, 19, of West Chester Twp., and two West Chester Twp. juveniles with juvenile deliquency by way of involuntary manslaughter and illegally manufacturing or possessing explosives.

"Moser is the one who lit it and the rest of them scurried," Oakes said.

None of the four teens had a previous criminal record, he said.

Moser was held in the Butler County Jail on a $35,160 bond Wednesday night. He will be arraigned in Area III Court on Tuesday and is free on bond.

The two juveniles were transported to the Butler County Juvenile Detention Center.

The juveniles, ages 14 and 15, both appeared before Butler County Court Juvenile Magistrate John Brewer Thursday morning where they entered a plea of "not true" or not guilty. They will be back in juvenile court at 10:30 a.m. Jan. 24 for a pretrial hearing.

The boys were released on home incarceration where they will be closely monitored until their next court appearance, according to Tim Myers, director of juvenile court services.

Myers said the boys have no past contact with the court.

Ferraro, the son of Anthony and Katherine Ferraro, was an Eagle Scout, a 2006 Lakota East graduate, and a sophomore ROTC member at Miami University studying psychology.

"He was a wonderful kid," said a volunteer with Ferraro's Boy Scout Troop 974, whose son is among a group of teens questioned by investigators following the accident. "They're a wonderful family. I hate to see this happen."

The explosion caused damage to the back of the home and shattered at least one window at an adjacent house.

Herzog said the explosion remains under investigation.

Police and emergency crews responded to the call at about 2:19 p.m. Detectives worked through the night processing the scene and piecing together what happened.

Friends at the scene said the Ferraros are active in the community. Katherine Ferraro teaches sign language at Lakota East High School and Anthony Ferraro is the scoutmaster with the Boy Scout troop where his son earned his rank of Eagle.

"They're the kind of people who give all the time. The kind of people who you call on when you need something," said a close friend.

Bureau of Alcohol, Tobacco, Firearms and Explosives agents, the State Fire Marshal's Office and the Butler County Sheriff's Bomb Unit were on the scene assisting in the investigation.