A 55-year-old female passenger commuting to work in northwest Colorado was killed Wednesday when a boulder fell on the car she was driving in, authorities said.
The incident happened around 7 a.m. local time, when the rock fell through the roof of a 2004 Buick, KDVR.com reported. She died at the scene.
The car was driving on one of two detour routes created after a rock slide closed Interstate 70 indefinitely in Glenwood Canyon.
Workers are trying to break up a huge boulder threatening to tumble down a cliff onto Interstate 70.
State officials say they hope to dislodge the boulder Wednesday and then decide when they can reopen some lanes.
The boulder is 20 feet in diameter and 900 feet above the highway. Workers will break it apart with compressor-powered drills hauled to the site by helicopter.
A 17-mile stretch of I-70 has been closed since Monday after the slide rained boulders onto the road and punched gaping holes in an elevated section.
The Associated Press contributed to this report.