A fatal rollover crash on U.S. 36, located at Lefthand Canyon Drive, has left two adults dead and two children injured.

According to a press release from the Colorado State Patrol Public Affairs Office, the accident happened at approximately 9:45 a.m. on Wednesday when a Jeep went through the center grass median before rolling and coming to rest in the southbound lanes of U.S. 36.

Both adult occupants of the vehicle, including the driver, were pronounced dead at the scene. Two passengers, ages 11 and 16, were identified as the children of the deceased and were taken to a hospital with moderate injuries.

The crash initially closed U.S. 36 in both directions between Nelson Road and Neva Road. As of Wednesday afternoon, the southbound lanes remained closed at Lefthand Canyon Drive and motorists were being warned to expect delays as the investigation continued.

The Boulder County Coroner’s Office will release the names of the deceased after notifying family. Investigators are working to determine what caused the Jeep to leave its lane and roll over.

The Colorado State Patrol encouraged drivers to use alternative routes while the southbound lanes remained closed.