Explosion of a car in Allentown, Pennsylvania: The father of a 2-year-old son is among those who were killed when a car caught fire

ALLENTOWN, Pa. – Police in Allentown, Pennsylvania, try to understand why a car caught fire over the weekend, he killed a father, his son and another man nearby.

The explosion rocked a neighborhood Saturday night, smashing windows and turning a vehicle into a twisted fireball.

"I just heard the explosion.A big explosion, like, it scared me, it surprised me.I thought it was like a house that has burst, "said a witness.

On Monday, authorities named the three victims: Jacob Schmoyer, 26, and his 2-year-old son, Jonathan, were in the car that exploded. Investigators said the third victim, 66-year-old David Hallman, who knew Schmoyer, was near the vehicle.

"The scene was probably the most horrible thing I've ever seen.It was a big scene that involved a lot of evidence, so it takes a while to process it," said the head of the Allentown police, Tony Alsleben.

At least 50 federal agents help local authorities search for clues about the cause of the blast. But they excluded terrorism.

"We know that we are dealing with a material that has exploded, a lot of energy has exploded," said Don Robinson, special agent of the ATF. "It could be anything, from an accident to a device."

Police believe that it is an isolated incident and that there is no more threat to the public. But the authorities said that if this explosion had occurred in a different area at a different time, the result could have been much worse.