Members of the Belmont Hills Fire Company and Gladwyne Fire Company responded to an accident on Interstate 76 at around 3:00 a.m. along with Pennsylvania State Police. All lanes were closed following the crash.
A Jeep Grand Cherokee drove through the scene approximately 20 minutes later, striking three firefighters from the Belmont Hills company and one state trooper, according to a Lower Merion press release.
EMS units immediately responded, but one of the firefighters, Tom Royds, went into cardiac arrest at the scene, officials said. He was taken to Paoli Hospital, where he passed away.
The other firefighters and the state trooper were taken by helicopter to Penn Presbyterian Medical Center in West Philadelphia, where they underwent surgery.
Firefighters gathered at their station to mourn the loss of their colleague as the flag flew at half-mast following the crash, ABC 6 reported.
Jacquelyn Walker, the driver, was taken into custody at the scene, and the investigation is ongoing. She has been charged with homicide by vehicle and related charges.
The original incident on Interstate 76 was possibly related to drunk driving, but there has been no indication of intoxication regarding the second crash, the Philadelphia Inquirer reported.
State Police did not respond to Fox News' request for comment.