Colorado’s first major snow storm Thursday already claimed a victim, according to the Colorado State Patrol (CSP).

Troopers tweeted at 7:46 a.m. Thursday I-70 was closed at Georgetown as they investigated a fatal crash involving a jackknifed semi-truck and a pedestrian.

I-70 westbound lanes were closed for hours while officials investigated the incident. The left lane opened at Georgetown at 10 a.m. and lanes fully reopened at 11 a.m.

A CSP spokesperson said the 56-year-old man was putting chains on his semi-truck when a driver, 26, hit and killed him when his vehicle lost control. The Clear Creek Coroner will release the victim’s name when next of kin are notified.

The semi-tractor trailer truck in the crash wasn’t the first this season to fall victim to the snowy high-country roads. U.S. Highway 40 Rabbit Ears Pass will close Friday morning to allow trooper and heavy-equipment operators to remove a truck that slid off the road and down the mountain Thursday morning.

Chain and traction laws were in effect Wednesday night and all Thursday, according to CSP. Drivers are urged to slow down and stay alert in the winter conditions.