The truck driver who caused a historic Indiana bridge to collapse because she wasn’t sure how much six tons weighed has been sentenced to jail.

Indiana Judge R. Michael Cloud sentenced 24 year old truck driver Mary Lambright to the maximum sentence of 180 days behind bars. She was also ordered to pay $2000 to cover part of the costs of the bridge inspection once construction on the new structure is completed.

The bridge collapsed over a year ago as Lambright was hauling 43,000 pounds of bottled water through Paoli, Indiana, on Christmas Day in 2015.

Lambright told police she was headed to Walmart to park her truck but missed her exit. After making several turns, she entered a parking lot to turn her truck around to try to get back to the Walmart. The parking lot she turned into was too full for her to make the turn, so she drove onto the iron bridge that spans Lick Creek.

The bridge sheared the top of the trailer off while the weight of the truck collapsed the structure. Police believe that she was traveling at about 30 m.p.h. when she began crossing the bridge.

Lambright and her 17 year old female passenger were not injured.

Lambright told police that she saw signage about the bridge’s maximum 6 ton weight limit, but that she was not sure how many pounds made up 6 tons. The bridge had a no truck sign posted as well.

She also told police that she was uncomfortable backing her truck up, which was why she chose to drive it across the tiny bridge instead.

Lambright lost her job over the incident.

She pled guilty to charges of reckless operation of a tractor-trailer, disregarding a traffic control device, and overweight on posted bridge earlier this year.

“I’m really, really sorry about what happened and, if I could go back and do it over again, I wouldn’t be so stupid,” she told the court.