SAN DIEGO (KSWB/KUSI) The Coast Guard on Tuesday suspended its search for six people who were reportedly aboard a small plane that crashed into the Pacific Ocean off the San Diego coast Sunday afternoon.

The Coast Guard suspended its search at 10 a.m. Tuesday, after rescue crews searched for over 35 hours through more than 300 square miles of ocean.

All six people who were on board the Cessna 414 aircraft that went down around three miles off the coast of Point Loma in San Diego just before 12:45 p.m. on Sunday are presumed dead, according to the Federal Aviation Administration.

“The decision to suspend a search is never an easy one,” said Lt. Cmdr. Justin Brooks, a search and rescue mission coordinator at Coast Guard Sector San Diego. “We appreciate the work of our partners throughout the search efforts, and our hearts are with the loved ones of those involved in the crash.”

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

The Cessna was registered to Optimal Health Systems out of Arizona.

The Coast Guard said several rescue crews were involved in the search:

• Coast Guard Air Station Ventura MH-60 Jayhawk air crew
• Coast Guard Air Station Sacramento C-27 Spartan air crew
• Coast Guard Cutter Sea Otter crew
• Coast Guard Station San Diego 45-foot RB-M crew
• Coast Guard Maritime Safety & Security Team 29-foot RB-S crew
• Customs & Border Protection Air & Marine Operations crews
• San Diego Harbor Police boat crews
• San Diego Lifeguards

The plane crash remains under investigation by the National Transportation Safety Board.