MONTGOMERY COUNTY, Pa. (CBS) – A jack-knifed tractor trailer created a traffic nightmare on the Pennsylvania Turnpike early Thursday morning.

The crash happened at about 4:30 a.m. in the westbound lanes of the Turnpike between the Fort Washington and Mid-County exits. All westbound lanes were shut down until they were reopened at about 8 a.m.

Authorities say the tractor-trailer driver somehow lost control and hit the median before veering off into the shoulder.

It was not immediately known if the driver was injured.

As a result of the crash, the tractor trailer leaked gas and oil, which forced clean-up crews to lay down sand to sop up the liquids.

All westbound lanes were closed due to the crash for nearly four hours.

The exact cause of the crash remains under investigation.