A house explosion in northern New Jersey that shook a neighborhood has killed one person and left two severely burned and in critical condition, officials said Wednesday.

The person who died was an adult male, Elizabeth Mayor Chris Bollwage said. He did not immediately release the man's name.

In all, 15 people went to hospitals, including an 11-year-old, the mayor said.

One person was unaccounted for, and firefighters were combing through the rubble for any sign of the person, who may have left the scene voluntarily, the mayor said.

The blast leveled the two-family duplex on Magnolia Avenue "like a pancake," Bollwage said. Swarms of fire trucks and rescue trucks crammed the street where the explosion occurred, a scant 100 yards from the busy Routes 1 & 9 corridor.

The explosion happened on the second floor and the mayor described it as a gas episode. However, a preliminary investigation by Elizabethtown Gas hasn't linked the explosion to a natural gas leak, said the utility's spokesman, Duane Bourne.

The investigation was ongoing.

The blast damaged seven homes and three would need to be demolished, Bollwage said.

The names and ages of the victims have not been released.

Lisset Garcia, who lives about two blocks away, said she was in bed with her daughter when the explosion occurred.

"I heard a loud boom and the house shook a little," Garcia said. "At first, I thought it was a small earthquake or something."

Kayon Pryce, who owns the house next door, said the blast knocked him over.

"I got hit in the face by my TV set," Pryce said. "The explosion actually tossed my bed upward, tossed me out of bed and knocked my phone out of my hand. I'm just happy to be alive."

Price said he heard a woman next door screaming and saw her rescued by firefighters a few minutes later.