Pennsylvania Army Depot Explosion Injures 4

FRANKLIN COUNTY, PA — An explosion at the Letterkenny Army Depot in Chambersburg left four people injured, three of whom had to be airlifted to hospitals, officials said. Fire officials said the three victims who were airlifted suffered burns.

At a press conference Thursday morning, an official at the depot said the incident happened around 7:20 a.m. and categorized it as a "small explosion" followed by a subsequent fire. The fire happened in a production facility at the depot.

The official said terrorist activity was not suspected. The cause of the explosion is under investigation.

The depot, located 160 miles (257 kilometers) west of Philadelphia, or about 55 miles (88 kilometers) southwest of Harrisburg, employs about 3,600 people. The depot's website says work there focuses on air defense tactical missile ground support equipment, mobile electric power generation equipment, Patriot missile recertification and route guidance vehicles.

The Associated Press contributed to this report.

Patch will update this report.