Two people were seriously injured in a crash involving a semi-truck and a sedan in southern Colorado Springs Saturday morning, according to police. 

The crash happened around 11:45 a.m. on South Union Boulevard near the interchange with Highway 24. A semi was headed northbound when the driver attempted a U-turn, according to police. The sedan, which was also headed northbound, hit the trailer and became wedged beneath it. 

Police said the four people in the sedan–a mother and her three children–were all trapped and had to be removed. Two of the children sustained serious injuries. 

Police said they don’t think the driver of the semi was impaired in any way. 

The road was closed for about seven hours while police investigated the crash and cut apart the vehicles involved. 

No charges have been filed. Police said their investigation is continuing.