OHIO TWP, Allegheny County — A Butler County woman was apparently driving the wrong way Monday night when she collided head-on with another car, killing her and the other driver, authorities said.

Amy L. Tua, 45, of Lancaster Township and Gary Helba, 42, of Pittsburgh were both pronounced dead at the scene of the crash just before 8 p.m. on Interstate 279 in northern Allegheny County.

State police said the accident occurred in the southbound lanes of the highway between Interstate 79 and Camp Horne Road in Ohio Township.

Investigators believe Tua was driving north. But police did not immediately know how or where she got onto that stretch of I-279, known as the Parkway North.

A flash flood warning had been issued for portions of the county, but it wasn’t immediately clear if weather might have played a role in the accident.

The collision was so severe, authorities said, that rescue crews had to cut open both vehicles to get to the drivers.

The parkway’s southbound lanes were shut down for several hours after the wreck.