TAMPA, Fla. (WFLA) — A Tampa woman and a Good Samaritan from Pennsylvania died following a series of crashes on U.S. 301 in Thonotosassa Thursday morning, the Florida Highway Patrol said.

The initial crash happened just before 3 a.m. in the area of U.S. 301 and McIntosh Road.

Troopers said a 32-year-old woman was heading north on the highway when for unknown reasons she crossed the center line and went into southbound traffic. Her SUV hit a pickup truck head-on, causing it to catch on fire.

The woman died at the scene.

Minutes later, a tractor-trailer that was heading northbound slammed into her SUV and also hit a pedestrian who had stopped to help the victims. Then it sideswiped another pickup truck that was heading southbound, the Highway Patrol said.

Florida Highway Patrol

The Good Samaritan, a 53-year-old man from Levittown, Pennsylvania, was airlifted to the hospital, where he died.

The driver and a passenger in the first pickup truck were also airlifted to the hospital and are being treated for serious injuries. The driver of the tractor-trailer suffered minor injuries.

The crash shut down a stretch of U.S. 301 for several hours, but the roadway has since reopened.