(WSBT) A section of a major highway remains closed after a semi accident caused big safety concerns. Police now say a stretch of U.S. 31 in Marshall County could be closed for days. One of the semis involved was carrying flammable liquid gas.

The collision happened Monday afternoon on U.S. 31 between Argos and Plymouth.

Police say the semi carrying the natural gas was making a precautionary stop at a railroad crossing, when another semi hit it.

The road is now closed in both directions for half of a mile on either side of 14th Street.

People who live near the crash were evacuated, but Tuesday afternoon firefighters determined the leak is isolated to a specific area, so people are allowed to go home if they want.

The crash happened more than 24 hours ago, but they're still not letting anyone within 1/4 of a mile from the scene, and they don’t expect that to change for at least another 24 hours.

"They just said there was gas and there could be an explosion and there could be gas leaking and they were concerned,” explained Johnny Dubois.

Dubois and his wife evacuated Monday after police warned them about an accident near their home.

“At this point we're not going to do anything until it’s completely done,” said Asst. Chief Cal Barker of the Plymouth Police Department. “We have a company coming that's going to purge the tank, make sure it’s safe to move the two vehicles from each other.”

As the leak evaporates into the air, this busy stretch of U.S. 31 is closed, leaving cars and trucks to take a new route around.

"We don't know how saturated or how frozen the asphalt is, so until we get a few of those answers, at this point we're not sure,” Barker said.

In the meantime, Dubois decided to take the risk and stay in his house.

“I had to be home and I wasn't really worried about it,” he said. “Obviously it wasn't a problem because nothing has happened so far."

A skeleton crew will remain on the scene overnight, including a HazMat team that is constantly checking the air quality.