A tanker truck carrying an estimated 10,000 gallons of gasoline overturned and caught fire Tuesday on the off-ramp of Iowa Highway 330 leading onto U.S. Highway 30 eastbound.

Marshalltown Fire Department Acting Deputy Chief Steve Edwards said the driver of the tanker was transported to the Marshalltown Medical and Surgical Center, 3 S. 4th Ave. The driver’s condition has not been released.

The tanker fire sent up a black plume of smoke that could be seen from 20 miles away.

Assistant Fire Chief Jim Vellinga of State Center said six fire departments responded, including one from Story County.

Vellinga said firefighters used a defensive strategy by not using water and letting the fire burn itself out, which he estimated would take six to eight hours.

Edwards said using water on the fire would have had a detrimental effect on the environment, spreading gasoline onto the surrounding area and under the overpass.

Bystanders said the off-ramp was known as an accident-prone area.

“I won’t go on that damn thing and I’ve lived here all my life,” said Don Ainsworth, Marshalltown resident.

Ainsworth said the off-ramp is dangerous because the speed limit goes from 55 miles per hour to 20 miles on the off-ramp very quickly. Also, the design of the interchange confuses drivers, he said.

“I don’t know how the [Department of Transportation] let this thing get designed,” Ainsworth said.

Jerry Sagar, resident of Marshalltown, said there had been numerous accidents on the off-ramp prior to this one.

“I’m surprised there haven’t been more people killed,” he said.

Vellinga said the Department of Transportation is investigating the interchange but he would not personally comment on it.

The Marshall County Sheriff could not be reached for comment.

The Red Cross and Salvation Army were on the scene with water to relieve firefighters in the 90-degree heat. Many firefighters sat in the shade of nearby grain bins to escape the heat of the sun while watching the blaze.