Four people were killed in a fiery single-vehicle crash early Saturday in Long Beach, authorities said.

It happened around 1:18 a.m. in the area of East Spring Street and Lakewood Boulevard.

Long Beach police said officers responded to the scene and found a gray sedan that had left the southbound lanes of Lakewood Boulevard and slammed into a concrete median inside the tunnel underneath the airport. Firefighters said the car caught fire after the collision.

Long Beach firefighters found four people inside the gray sedan and pronounced them all deceased at the scene. They were not immediately identified.

“It was just mangled. It looked like a mess. Firefighters were there just trying to do their best to extinguish it. I believe they even dragged a body out of the vehicle as well,” one witness said.

Investigators say it’s too early to know exactly what caused the crash.

In a statement on Saturday, Long Beach police said, in part: “At this time, speed and impairment are being investigated as possible factors in the collision.”

Lakewood Boulevard was closed for hours as collision investigation detectives worked the scene.

“I’ve personally experienced a lot of young drivers over here who are racing through those particular tunnels, even though other one on the opposite side,” said Long Beach resident Victoria Payne.

Neighbors say speed has been a frequent problem in the area, but are still devastated to hear the news that four people died on a street so close to home.

“We drive that, me and my husband take that way home, and he goes to work at 12:30 midnight. It’s always a wonder like, is other people aware of how dangerous it can be, and just making sure that you’re driving safely,” Payne said.

In a rare move, the National Transportation Safety Board (NTSB) is now investigating alongside Long Beach police.

Eyewitness News asked whether that was due to the road’s history or its proximity to the airport.

In a statement, the NTSB said, in part: “The NTSB regularly investigates roadway and highway crashes to identify safety issues that could have nationwide impacts and to develop recommendations to prevent similar crashes.”

For neighbors, the hope is that answers come and that changes follow.

“We have a lot of young drivers who want to experiment because it is a tunnel. They think it’s harmless, and they don’t understand how dangerous that it can be if it gets out of control, and you can’t control your car, and you could really hurt yourself,” Payne said.

The NTSB says a preliminary report is expected within 30 days, with a final report possibly taking a year or more.