SAN DIEGO (FOX 5/KUSI) The multi-agency search is continuing Monday for six people who were on board a Cessna 414 aircraft that went down off the coast of Point Loma over the weekend.

The plane crash was reported just before 12:45 p.m. on Sunday. According to U.S. Coast Guard officials, the aircraft fell into the Pacific Ocean about three miles west of Point Loma.

The National Transportation Safety Board was called to investigate what caused the plane to go down into the water.

Meanwhile, Coast Guard search and rescue assets, including those from partner agencies such as the U.S. Border Patrol and San Diego lifeguards, were deployed to scour the area for the aircraft and any survivors.

According to the flight tracker, FlightAware, the Cessna appears to have been bound for Phoenix, Arizona, departing from San Diego International Airport just 15 minutes before it went down in the Pacific Ocean.

An audio recording of what appears to be the conversation between the pilot and air traffic controllers, which was archived on the live air traffic website LiveATC.net, indicates the aircraft was flying at an altitude of about 1,000 feet prior to its descent into the ocean.

The air traffic controller can be heard directing the pilot to bring the aircraft up to 4,000 feet, but the pilot responds, saying he is “struggling” to maintain altitude. The controller then suggests the pilot land at Naval Air Station North Island, but shortly after, the pilot sends out a mayday call.

At this time, it is unknown who was on board, including its pilot. NTSB officials have not yet released any additional information regarding their investigation into the crash.

Federal Aviation Administration records indicated the more than 50-year-old aircraft is registered to an Arizona-based nutritional supplement company, Optimal Health Systems.

In a statement, Optimal Health Systems founder Doug Grant said the plane had been sold to a group of private individuals back in 2023 and had been in escrow up until recently. Federal records had not yet been updated to reflect the change in ownership.

However, Grant added he “personally knew several of the passengers onboard” and offered condolences to those affected by the tragedy.

“Our thoughts and prayers are with them and their loved ones,” he said. “Again, we extend our sympathies to the victims and their families during this difficult time.”

This is a developing story. Check back for updates.