Update:Huge Pottstown house explosion in Pennsylvania leaves 4 dead, 2 injured

Firefighters and emergency crews rushed to the scene around 8:00 p.m. local time

The explosion happened in the 400 block of Hale Street, destroying at least one house 

Pottstown Borough Manager Justin Keller confirmed the fatalities during a press conference

Resident Christian Gonzalez told ABC News Philadelphia station WPVI he initially thought the explosion was thunder

Police have not identified the victims yet. Pottstown is located about 40 miles northwest of Philadelphia

Two additional people may be unaccounted for, Pottstown Borough Manager Justin Keller said

Montgomery County officials said they believe a gas leak may have caused the house to explode