The National Transportation Safety Board (NTSB) is investigating a natural gas pipeline rupture incident that caused a fiery explosion on Sunday, bringing a Union Pacific Railroad train, which was carrying hazardous materials, to a halt just feet from the blaze. 

The explosion occurred just after 1 a.m. near mile marker 350 on Interstate 80, west of Cheyenne. The resulting fire was visible from up to 60 miles away, prompting many emergency calls. 

Early reports from callers suggested the train was on fire, but Union Pacific spokesman Mike Jaixen clarified Monday that the train was stopped approximately 40 feet from the rupture.

“The heat from the fire made it too dangerous to operate over the track,” Jaixen said in an email. “There was no derailment and no one was hurt.”

While Union Pacific declined to specify the train's cargo, Laramie County Fire District 10 officials confirmed the train was carrying hazardous materials, which heightened the risk for first responders. 

Firefighters from three different agencies in Laramie County and Cheyenne quickly responded and contained the fire, with the incident currently under investigation by the NTSB to determine the cause of the pipeline failure. 

Authorities have praised the swift actions of emergency personnel in preventing a more severe incident involving the hazardous materials on the train. 

The immediate area was secured following the incident. No injuries were reported, and no hazardous substance was leaked.