Explosion levels home in Westfield, New Jersey. Video shows damage left behind.

WESTFIELD, N.J. -- An investigation is underway after a house exploded and the wreckage burst into flames overnight in Westfield, New Jersey. 

The cause of the explosion still hasn't been determined. 

Fire officials say debris was tossed out of the home and scattered over the front lawn. They say that's a sure sign of an explosion, but are not sure if a gas leak was the cause. 

Explosion rocks Tudor Oval neighborhood

The house exploded around 10:15 p.m. Monday on Tudor Oval, sparking a raging fire. The moment it happened was caught on surveillance video. By daybreak, video showed the roof on the ground and debris scattered all over the yard. 

"Just the loud explosion, and just popping some sparks. It just went quickly," Westfield resident Maria LoGrippo said. 

"When you looked in just the hole in the front of the house, and inside you could see the flames starting, and the front door was kind of on the lawn, and I called 911 immediately," Francesco LoGrippo said. 

They were immediately concerned about the house next to the home on fire. 

"The wind was going away from that house. That house is really close, and they have two small babies right there. Everyone was safe," Maria LoGrippo said. 

Debris was blown out of the home and on to the front lawn. Neighbors said it's a miracle that the fire didn't spread. 

"The flames started small, and then they kept getting bigger. The trees and and bushes around the house were dead, so it kind of spread like a wildfire," Francesco LoGrippo said. 

Wreckage being removed

Crews could be seen working in front of the building Tuesday, tearing the house apart with heavy equipment. Residents said the home has been vacant for more than a decade, and hasn't been kept as well as it should be. 

"An older couple owned it, and now their son comes by every once in a while and mows the lawn, but he doesn't live there," resident Mary Wickens siad. 

The son in question disagreed, and told CBS New York's Christine Sloan the house was well kept. 

Residents said the only thing out of the ordinary last week was a repaving of the street. 

Local, county and state fire officials are trying to determine what happened. 

Union County officials and Elizabethtown Gas say the area is safe, but some neighbors decided to evacuate while the cause remains under investigation.