Two Pathmark employees were shot and killed early this morning in Old Bridge, New Jersey, by a disgruntled coworker who then took his own life, the township's mayor said.

"This is the worst phone call a mayor can receive," Mayor Owen Henry told the Star-Ledger. "You can prepare for these things but you can't prevent them."

The shooting took place around 4 AM inside the Pathmark shopping center at Route 9 and Downing Street. The store was closed at the time, but employees were inside stocking shelves.

The gunman, identified by WABC and NBC New York as a 23-year-old ex-Marine who had been employed at the store for the past two weeks, entered the store armed with an AK-47 and an automatic handgun. He was also said to have been wearing body armor and camouflage.

The victims' identities have not been released, but they are both believed to be young adults in their late teens or early twenties.

The remaining employees were escorted to a nearby TGI Fridays, and the neighboring Old Bridge Park & Ride was temporarily closed while the investigation continued, but has since been reopened.

UPDATE: The shooter has been identified as 23-year-old Terence Tyler of Old Bridge Township. His two victims were an 18-year-old woman and a 24-year-old man, also of Old Bridge. Tyler reportedly left after finishing his shift at 3:30 AM, returned a half-hour later, and began firing indiscriminately at his fellow employees.

[screengrab via NBC News]