A motor home caught fire and set off three explosions, crippling I-94 for hours between Osseo and Black River Falls. The fire also destroyed a car the motor home was towing and started a grass fire.

Investigators believe the RV was leaking diesel when the engine compartment caught fire. The flames spread quickly to the car being towed behind the RV and caused major problems on the interstate. The State Patrol says there's evidence fuel was leaking onto the interstate before the fire started. Eyewitnesses say the blazing wreck blocked the entire road.

Troopers had to shut down the Interstate on a busy holiday weekend, trapping hundreds of travelers in the Friday heat. Investigators say just after 3 p.m., the two men in the RV noticed something was wrong.

"The people inside just said that they started smelling smoke and that they went to the rear of the RV when they pulled over and it was already on fire,” says Jackson County Sheriff Duane Waldera. "They tried to put it out with a fire extinguisher inside the RV, and it was too much engulfed already. They had to leave the RV."

State troopers and firefighters arrived in minutes. When they pulled up, the RV and vehicle were both on fire. Fed by diesel, the fire quickly got worse.

"There’s at least 3 small explosions. (It’s) unknown what really exploded. The fire then spread from the vehicle onto the dry grassy area,” Waldera adds.

He says before the driver could pull over, the RV was already leaking diesel. The mess stretched for hundreds of yards along the right lane. Highway crews put down sand to absorb the fuel and then had to brush it off before the state patrol could open the lane.

The two men who were in the RV and their two dogs are all ok. Troopers say the men are from Colorado and were headed there. State Patrol is still investigating the crash. While firefighters were putting the fires out, troopers detoured traffic for miles, but both lanes are now open.