US police have arrested a man after a boulder allegedly bounced out of the bed of his truck and crashed into another car, killing two people.
Joseph Paul Czeck, 33, failed to stop after the accident and was arrested two days later. Police say photos of his rock-laden truck led to the arrest.
The 800-lb (360kg) rock rolled into a car carrying a mother and her daughter in a suburb of Minneapolis.
Karen Christiansen, 67, and Jena Christiansen, 32, died at the scene.
The accident occurred on Monday afternoon on a rural stretch of road in Rosemount, Minnesota.
As the lorry rolled over railway tracks, the boulder flew off, crashing into the family’s vehicle, Rosemount police said in a news release.
Police Chief Mitchell Scott told local media that the rock was so heavy that it took four firemen to roll it off the road.
“This could have been prevented if the load had been secured,” he said.
Investigators visited local construction sites where they were able to determine that the vehicle belonged to Czeck Services, a landscaping company.
Mr Czeck was arrested on Wednesday, and so far has declined to give a statement to investigators. He will have his first court appearance later on Friday.