CORDES JUNCTION, Ariz. — Authorities say two drivers who stopped along an Arizona highway to help following an accident were killed when struck by a tractor-trailer rig changing lanes because of the stopped vehicles.

State Trooper Kameron Lee says the wreck occurred Tuesday night on southbound Interstate 17 about 70 miles north of Phoenix after a big rig jack-knifed when the driver lost control in heavy rain, partially blocking the left lane.

Lee says three cars’ drivers stopped to help and parked on the right shoulder with their flashers on.

According to Lee, another big rig struck the cars after seeing their flashers and changing lanes before striking the mostly dark jackknifed truck.

Lee says five other people in the cars were injured, one critically. No identities were released.