LOVELAND, Colo. (CBS4) – A portion of Interstate 25 near Loveland was closed in both directions more than 36 hours after a semi-truck crashed on Saturday and spilled 11,500 gallons of diesel. The crash happened at 1:12 a.m., and investigators believe the 67-year-old driver fell asleep at the wheel. John Brothersen of Henderson was cited for careless driving, according to the Colorado State Patrol.

(credit: Loveland Fire Rescue Authority)

“At this time, driver fatigue is being considered the primary factor,” the CSP stated.

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“Driving while fatigued is comparable to drunk driving. And, falling asleep is the worst scenario that often leads to large-scale or tragic consequences,” stated Captain Mark Bonfield.

The driver, CSP says, suffered serious injuries and was trapped at one point in the cab of the truck.

The Environmental Protection Agency said the fuel spilled into a drainage ditch and storm drain that lead to the Big Thompson River. The EPA set up several collection areas to determine if any of the fuel is seeping into the watershed. At this point, the agency calls it all proactive measures.

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“We’re just not seeing anything that would lead us to believe that we have any concerns with the water right now,” Joni Sandoval said.

However, the the diesel did cause damage to the roadway.

“The fuel, when it gets into the pavement, when it’s that massive amount of levels, seeps down into the pavement and actually gets to the sub surface,” Jared Fiel said. Fiel is the Regional Communications Manager for the Colorado Department of Transportation.

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Crews repaved and restriped both sides of the interstate.

Anica Padilla