Police say dense fog caused a series of accidents on the Lake Pontchartrain Causeway during rush hour traffic Thursday morning.

There was a total of six accidents over a span of 45 minutes on the southbound lanes of the Causeway starting at 7:40 a.m.

The first crash happened near the 7-mile marker involving two vehicles. Seven minutes later, a second crash happened near mile marker 9 due to the first wreck.

Police say a drunk driver caused the third crash. The driver of a white van was driving carelessly, stopped and struck a guardrail on the southbound lanes.

At around 8:19 a.m., a vehicle overturned near the 12-mile marker. The driver of the vehicle was taken to the hospital.

Minutes later, police responding to the overturned vehicle were rear-ended by another vehicle.

Another two-vehicle crash happened around 8:26 a.m.

Causeway leaders blame dense fog as the cause of the crashes. Drivers are urged to pay extra attention while driving on the bridge in low visibility.

The Causeway has reopened after the crashes. Both northbound and southbound lanes are limited to single lanes due to the dense fog.