UTICA, Neb. (AP) — Authorities blame speed and a slippery pavement for a collision between a pickup truck and a semitrailer that killed four people on Interstate 80 in eastern Nebraska.

The crash was reported around 7:15 a.m. Tuesday between the Waco and Utica exits, hampering westbound traffic.

Lt. Paul Vrbka with the York County Sheriff’s Department says the three males and one female killed were from Colorado. Their names aren’t being released until relatives have been notified of the deaths.

Vrbka says the eastbound pickup went out of control and crossed the median into the westbound lanes, striking the semitrailer and killing its four occupants. The big rig driver wasn’t injured.

Icy pavement played havoc with Tuesday’s morning commute in many parts of eastern Nebraska.