FORT WORTH (CBSDFW.COM) – A big rig jackknifed in the southbound lanes of I-35W near Northside Drive.

It happened just before 6 a.m. Tuesday.

MedStar said the driver was able to get out safely.

The ramp to Northside Drive was closed while police and fire crews worked to clean up the scene.

No word yet from police on what happened.