SARDINE CANYON — Heavy rain Friday night sent two boulders about the size of a sedan tumbling onto the highway up Sardine Canyon, ultimately causing a half dozen accidents and minor injuries.

U.S. 89/91 was open Saturday, but the Utah Department of Transportation remained on the scene to monitor the hillside for other potential rock slides or movement.

Utah Highway Patrol Sgt. Mary Kaye Lucas the two boulders accompanied by rocks and other debris came down the hillside near Mantua about 9:50 p.m. Friday. The slide led to six crashes — none of them serious — and the closure of the roadway until officials could be assured there was no risk to public safety.

"If it keeps raining, they’ll probably see more sliding," Lucas said, adding the highway remained closed overnight because of the instability of the hillside.

UDOT officials gave the all-clear when they believed the hill had stabilized.

— Amy Joi O'Donoghue