A head-on collision on Avenue 7 near Road 22 in Madera County killed eight men shortly after 6 a.m. Friday, the California Highway Patrol said.

According to the CHP, the fatal collision was between a Chevrolet truck traveling east and a GMC van heading west toward Firebaugh.

CHP Officer Javier Ruvalcaba said that seven of those killed were farmworkers in the van. The other man killed was in a pickup truck, he said.

Failure to wear seatbelts contributed to the high fatality count, authorities said.

The collision closed Avenue 7 from Road 21 to Road 22.

(The Associated Press contributed to this report.)