SIOUX COUNTY, Iowa — A teenager was killed and another was injured in a crash in northwest Iowa on Tuesday afternoon.

The crash report from the Iowa State Patrol said the incident happened around 2:27 p.m. at the north junction of Highway 75 and Highway 18, about six miles east of Rock Valley.

A Cadillac Escalade driven by a 17-year-old was stopped at a stop sign on Highway 18, facing east, and then pulled out in front of a semi that was northbound on Highway 75. The semi struck the Cadillac, which came to rest in the east ditch.

The ISP said one 17-year-old in the Cadillac was transported to the Sioux Center Hospital, where they were pronounced dead. Another 17-year-old was transported by air ambulance to Avera McKennan Hospital in Sioux Falls. Their condition is unknown.

Both teens are from Rock Valley.

The ISP report did not list injuries to the driver of the semi.

The crash remains under investigation.