Officials with the Texas Department of Transportation and NorthGate Constructors say the Texan Trail bridge in Grapevine will remain closed indefinitely after it was damaged Thursday.

The driver of an 18-wheeler carrying a large piece of construction equipment unrelated to work on the DFW Connector misjudged the height of the bridge, officials said Thursday night, and the cargo slammed into the underside of Texan Trail's stretch over Hwys. 121 and 114 just north of the Dallas/Fort Worth International Airport. The damage to both the north- and southbound sides of the bridge makes it unsafe for traffic.

The highways beneath the bridge are shut down this evening as engineers get a better look at the damage and see if emergency repairs are possible.

NorthGate Constructors spokeswoman Kristen Schropp said that while the damage was not caused by anyone involved in the DFW Connector work, it could cause major problems for the $1.1 billion project.

The construction company had planned to move traffic to the west, southbound side of Texan Trail bridge this weekend, beginning Saturday morning, in anticipation of demolishing, rebuilding and expanding the bridge one side at a time as it has with the Main Street and William D. Tate Avenue bridges.

"We were going to demolish the northbound side anyway ... but right now we don't know what we're going to do about southbound," she said. "Work would go a lot faster if we were able to demolish the whole bridge and just rebuild it, but that would cause a traffic nightmare."

If engineers are not able to assure the safety of the southbound lanes, though, NorthGate will not have a choice. That could mean schedule changes for the construction team and longer detours for motorists traveling through the project in the coming months.

For now, motorists are being advised to take Main Street as an alternative. NorthGate plans to unveil that intersection's first Texas U-turn overnight Friday. Its reveal on the east side of the bridge should help ease the impact of the Texan Trail bridge closure.

For the latest updates on the Texan Trail bridge, check the project website at www.dfwconnector.com.