GREEN RIVER, Wyoming (AP) - Investigators in Wyoming commenced a meticulous examination of the wreckage within a highway tunnel on Saturday, as smoke, hazardous chemicals, and structural concerns hindered efforts to ascertain the number of casualties resulting from a devastating multivehicle crash that occurred on Friday.

Initial reports confirmed that at least two individuals lost their lives, with five others suffering serious injuries from the massive pileup. This tragic incident took place in the westbound tunnel of Interstate 80, located underneath Castle Rock, a notable snow-covered sandstone formation overlooking the town of Green River in southwestern Wyoming.

According to Maj. James Thomas of the Wyoming Highway Patrol, the scale of the incident necessitates a prolonged investigative process to ensure a comprehensive review. He noted, "It's really going to be a long process just because of the magnitude of the incident and then being able to document everything that we need to make sure that our investigation is thorough.” Due to the complexity of the wreckage, officials have not yet determined the total number of vehicles involved in the crash.

Photographic evidence captured at the scene on Friday depicted mangled semitrailers positioned outside the charred entrance of the tunnel, which spans approximately a quarter-mile (400 meters) in length. Randy Ringstmeyer, an engineer with the Wyoming Department of Transportation, reported severe fire damage affecting the middle third of the westbound tunnel. The intense blaze led to damage of its concrete lining, resulting in loose concrete falling into the tunnel, thereby necessitating cautious navigation on the part of first responders.

Traffic on the interstate is being redirected through Green River as a safety measure. Authorities aim to restore operations in the eastbound tunnel within a three-day timeframe, allowing it to accommodate two-way traffic while the westbound section remains under repair. However, engineers could not provide a timeline for when the westbound tunnel might be reopened.

In light of this catastrophic event, the National Transportation Safety Board announced that it has initiated a safety investigation in partnership with the Wyoming Highway Patrol to uncover the causes and factors that led to the crash.