Four people were killed and two others hurt in a house explosion Thursday night in Pottstown, Pennsylvania.

Multiple homes were damaged and at least one home was leveled in the blast. Crews were called to the scene at Hale and Butler Streets around 8 p.m.

The blast happened in close proximity to Pottstown Middle School and High School. The school district closed all schools for students and staff on Friday.

The American Red Cross was on scene to help families. The organization says it helped about 20 people in the area with food, shelter and assistance.

The cause of the explosion remains under investigation.