An investigation by the DEP and the EPA is underway into an explosion at the Langeloth Metallurgical Plant Thursday evening. Smith Township Fire Chief Brandon Kriznik said the explosion – in the 10 block of Langeloth Plant Road happened just after six, while a tanker was trying to transport chemicals. Firefighters said the spill was brought under control quickly, and because all chemicals were contained, nothing dangerous was released into the air and there is no threat to the public. Authorities say four people were hurt and taken to the hospital, and that included the truck driver and three plant employees, but they didn’t release any information on the nature of the injuries. The plant is currently shut down. Authorities say the blast was heard for miles.