Oklahoma City, OK – A girl was killed and her parents and brother were injured when their home in Oklahoma City exploded Thursday morning, fire officials said. The ages of the girl or her brother were not immediately released, but both are younger than 18, according to District Fire Chief Benny Fulkerson.

The explosion occurred just before 7 a.m. in northeast Oklahoma City and destroyed the home while also damaging at least three nearby houses, Fulkerson said.

The cause wasn’t known, but Fulkerson said the home had propane, not natural gas.

No names were released. The explosion did not appear intentional, Fulkerson said.