Niagara County Undersheriff Michael Filicetti said the blast occurred around 6 a.m. Tuesday at a home in the rural town of Wilson, on Lake Ontario about 30 miles north of Buffalo. The home used propane tanks but the cause of the explosion wasn't known yet, authorities said.
Sarah Johnson's body was found in the debris at the rear of the home, Filicetti said. Authorities weren't sure of her age but believe she was between 12 and 14.
Filicetti said her parents and two siblings were blown clear and were found in the front yard by the first deputy to arrive on the scene. All four were being treated at a Buffalo hospital for serious injuries, he said.
Two other children weren't home at the time of the blast, which Filicetti said could be felt at the sheriff's communications center about four miles away.
The explosion occurred on a sparsely developed stretch of rural road. Neighbor Nate Reynolds, 22, said he was sleeping when a loud noise woke him up. At first he thought it was thunder, but then soon began getting text messages from friends saying there was an explosion nearby.
"It's sounded like a sonic boom," said Reynolds, who lives about 100 yards from the explosion scene. "It shook my whole house."
Other neighbors said they heard and felt the blast, then saw a ball of flame rise over the house. Scores of firefighters from several local volunteer companies put out the blaze.
The force of the blast sent debris flying over a wide area. Yellow wall insulation and a soccer poster could be seen on neighboring lawns. A basketball backboard and hoop mounted on a black pole stood out against the pile of smoldering rubble where the house stood.