HASTINGS, Minn. (AP) — A Minnesota truck driver was sentenced Tuesday to 10 months in jail for the deaths of a mother and daughter who were killed when a boulder fell from his truck and smashed into their car in suburban St. Paul.

Joseph Czeck, 34, of Hastings, Minnesota, pleaded guilty last month to two counts of criminal vehicular homicide in the July 2018 deaths of 67-year-old Karen Christiansen and her 32-year-old daughter, Jena Christiansen, both of Shoreview, Minnesota.

The plea agreement accepted by the judge calls for Czeck to serve his jail time in two segments, the Star Tribune reported. Czeck will be allowed to participate in a sentence to serve program, which often means being part of a supervised work crew or doing other community work involving physical labor. He also must pay restitution and write a letter of apology.

“We are pleased to have brought this man to justice for this easily preventable crime on our roads, which tragically claimed two lives in our community,” Dakota County Attorney James Backstrom said in a statement.

As part of his business, Czeck was hauling unsecured boulders in the back of his commercial truck. When the truck crossed over railroad tracks, one of the boulders flew out of the truck bed, crossed the median and bounced into the windshield of the oncoming car in Rosemount, Minnesota.

The mother and daughter died at the scene. Czeck never reported the incident. Police arrested him two days later.