HOUSTON (AP) — Authorities say a man driving home following his 38th birthday celebration has died in a Houston-area wreck that left four of his friends hurt.

The Harris County Sheriff's Office says the traffic accident happened early Thursday. The pickup truck went off the road, hit a culvert and flipped into a wooded area.

Investigators are trying to determine what caused the driver to lose control of the truck after the birthday party Wednesday night at a restaurant.

Officials say two passengers who suffered serious injuries were transported to a hospital. The other two victims were treated at the scene.

Names of the man who died and the injured weren't immediately released.