All occupants of a semi truck are dead after a crash turned into a fire along westbound Interstate 70 in Summit County, closing the Eisenhower Tunnel’s westbound side on Sunday morning.

Colorado State Patrol officials said the crash occurred around 5:42 a.m. near the Eisenhower Tunnel. The crash, which took place at westbound milepost 208, closed the 1.7-mile long tunnel, causing westbound delays and backups Sunday morning, according to the Colorado Department of Transportation.

CDOT officials said the crash was a commercial vehicle crash and fire near Silverthorne.

In a news release, CSP officials said initial investigations indicate a semi with a trailer drove off the right side of the road, crashed and caught on fire.

Authorities said all occupants of the semi were pronounced dead on the scene.

“Due to the extensive damage and fire to this vehicle, first responders are unable to confirm the number of occupants at this time,” CSP officials said.

As of 11:15 a.m., westbound I-70 remains closed as the crash investigation remains ongoing. CSP officials warned of extensive delays and closures with no timetable for reopening. Colorado transportation officials ask motorists to detour along U.S. 6 over Loveland Pass.

CSP asks anyone who may have witnessed the crash to contact the agency at (970) 249-4392 with reference number VC250372.

This story is developing and will be updated.