Colorado State Patrol investigators released more details Friday about what happened leading up to Thursday's deadly fiery crash on I-70 in the high country. The crash between a RAM camper utility van hauling a trailer and a semi truck hauling an empty trailer happened about 1:30 p.m. Thursday in the westbound lanes of I-70 before the Eisenhower-Johnson Memorial Tunnels.  

According to CSP, the RAM was traveling westbound on I-70 in the right lane when it weaved onto the shoulder and struck the rear of the semi's trailer where the semi was parked. The semi was pushed forward slightly. 

The RAM caught fire and was engulfed in flames, with the driver and the dog trapped inside. Both the dog and the driver died. That person's identity has not been released. The driver of the semi did not report any injuries. 

The cause of the crash is still being investigated by the CSP Vehicular Crimes Unit. 

Both the westbound and eastbound lanes were closed after the crash. Eastbound lanes reopened about an hour after the crash. Westbound lanes remained closed for several hours, causing miles-long backups as people hit the road for the Fourth of July holiday weekend.