Eight people were killed before dawn Monday in a head-on collision between a box truck and a passenger van on a rural highway.

All of the eight killed were passengers in the van, Kemper County Sheriff James Moore told The Associated Press. They worked for an agricultural company and were planting trees, Moore said. Most were from Macon, Mississippi — about a 20-minute drive from the crash scene, he said.

“We had rescue workers there who said that out of 25 to 30 years they’ve been doing this, they haven’t had one this bad,” Moore said. “The van is pretty tore up.”

Both drivers survived and are expected to recover, Moore said. It’s not yet clear which vehicle crossed into the wrong lane, he said.

The Mississippi Highway Patrol received a call just before 3:30 a.m. Monday about the wreck on Mississippi Highway 16 east of Scooba, near the Alabama state line, Sgt. Andy West said.

Investigators were working to reconstruct how the accident happened. Weather is not believed to have been a factor, the sheriff said.

Volunteer rescue workers from Kemper County and from the nearby town of Philadelphia, Mississippi, responded to the crash.

“You do what you can to preserve the bodies with dignity,” Moore said. “After it’s over with, that’s when it starts to set in what you’ve just done.”