New Orleans — Both sides of the Lake Pontchartrain Causeway were closed for several hours Thursday while a 35,000-pound dump truck that exploded and went off the bridge Wednesday was pulled from the lake’s bottom.

The driver was not in the cab when the truck was recovered, and divers had not been able to find the body as of late Thursday, according to Carlton Dufrechou, Causeway general manager.

He said the driver, whose name has not yet been released, was returning to the south shore about 4:45 p.m. Wednesday when a driver headed northbound called to report a truck on fire and then said it had exploded. Eyewitnesses said the truck was lifted up into the air, Dufrechou said.

Dufrechou said Causeway police were on the scene immediately and the Jefferson Parish Fire Department, the U.S. Coast Guard and paramedics arrived within 30 minutes. Divers were in the water within 90 minutes, he said, and both sides of the bridge were shut down until 6 p.m.

On Thursday, the southbound span was closed at 10 a.m. to give the divers room and to accommodate the truck’s recovery. The Jefferson Parish Sheriff’s Office and St. Tammany Parish Sheriff’s Office worked the scene, he said. Two heavy lift trucks were strategically placed over the girders of the bridge to distribute the weight, Dufrechou said.

Dufrechou said he decided to close the northbound span shortly after noon because drivers were “doing silly things like trying to take photos with their cellphones and slowing down.’’

The truck had been pulled from the lake bottom by about 1:30 p.m., he said, and it took another 30 minutes to get it on the deck. The northbound bridge was reopened by about 3 p.m. and the southbound a few minutes later, he said.

The lake is about 12 feet to 14 feet deep where the truck went in, he said.

The dump truck is one of the larger vehicles to have plunged into the lake, Dufrechou said. But he noted that in the 1970s and 1980s, barges sometimes ran into the bridge, and in one such incident, a bus went into the water. That accident was the impetus for putting in a radar system.