BOZEMAN, Mont. (AP) — Law enforcement officers are investigating after a 22-year-old Montana man suffered fatal injuries after stepping into the path of a semitrailer on Interstate 90 near Belgrade.

The Gallatin County sheriff's office says Sha'Del Hollis of Bozeman was injured on Saturday morning and was declared brain dead the next day. He was kept on life support until his organs could be donated on Thursday morning.

Montana Highway Patrol Trooper Blaine Heavner said witnesses had reported someone darting in and out of traffic at about 7 a.m. Saturday. Minutes later, Hollis was struck.

Heavner says the driver of the semi tried slowing down and reported Hollis was walking back toward the shoulder of the road when he was struck by the right front corner of the semi.

The driver of the semi was not injured.