Authorities were investigating Monday after a small plane carrying six people crashed off the San Diego coast.

The twin-engine Cessna 414 crashed at around 12:30 p.m. Sunday, not long after it took off, the Federal Aviation Administration said. The plane was bound for Phoenix, according to the flight tracking website Flightaware.com.

Searchers found a debris field later Sunday about 5 miles (8 kilometers) off the coast of Point Loma, a San Diego neighborhood that juts into the Pacific, U.S. Coast Guard officials. The water in the search area is about 200 feet (61 meters) deep.

The Coast Guard said in its initial news release Sunday that it was searching for the six people on board, whom it didn’t identify.

A man who was out surfing when the plane crashed told NBC 7 in San Diego that he saw the plane come down at an angle, then climb back into the clouds before diving again and crashing into the water.

“The next time he came out of the clouds, he went straight into the water. But after I saw this splash, about six seconds later, it was dead silent. I knew that they went in the water, nose first, at a high speed,” Tyson Wislofsky said.

The crash comes less than three weeks after a small Cessna crashed into a San Diego neighborhood in foggy weather and killed six people.