It happened around 2:15 p.m. in the 100 block of Emmett Street in Phoenixville.
The view from Chopper 6 HD shows a number of windows blown out and caution tape over a lower level window.
At least one victim has been reportedly found at the scene. There is no word on the person's condition or identity.
A PennSTAR medical helicopter was dispatched.
There is no word yet on any other injuries or what caused the blast.
