The southbound lanes of Florida’s Turnpike were shut down Thursday morning following a serious crash involving a semi truck hauling mulch and three other cars.

The wreck happened on July 5th at around 5:11 a.m. in Fort Pierce, Florida.

The St. Lucie Fire District says that the semi truck rolled on top of another car, causing a wreck with two other vehicles, reported West Palm Beach News.

A man and woman were transported to a nearby hospital in serious condition while two other men sustained non life-threatening injuries.

The southbound lanes were reopened at around 8:35 a.m., but officials are still investigating the cause of the serous wreck.