On Thursday a plane flying across the Gulf of Mexico crashed into the ocean after being unresponsive to radio calls for hours. The pilot was the only person onboard the Cessna, and had been monitored by two F-15 aviators while the plane circled above the Gulf.

Heading from Slidell, La., to Sarasota, Fla., the plane became unresponsive at 9 a.m. EDT. At approximately 12:10 p.m. the plane crashed into the ocean, landing right-side up on the surface, reported CBS. While floating at first, the Cessna sank about 120 miles west of Tampa, Fl. The plane is estimated to be in about 1,500 feet of water.

The Coast Guard was dispatched, but the pilot has not been discovered, and is not believed to have survived the crash.  Authorities have yet to confirm who was flying the plane.

Chief John Edwards informed that while New Orleans National Guard jets were on a mission over the Gulf they received a call to check on the plane. The windshield of the Cessna was reported to be iced over as it was hovering between 25,000 and 35,000 feet near an Eglin Air Force Base.

According to ABC News, Thursday morning, John Cornelio, NORAD spokesman, said that We are monitoring the flight pattern and the aircraft remains unresponsive.  No information has been released on what may have gone wrong to cause the private plane to go down.

The Coast Guard will not release the name of the pilot for 24 hours once he has been identified, but according to CBS, the pilot is believed to be Dr. Peter Hertzak, an Ob-Gyn, who worked northeast of New Orleans. Slidell Airport mechanic, Bill Huete, told CBS that the only person who would have been a pilot in that plane would be Hertzak. Huete also revealed that Hertzak's wife told the mechanic that her husband would be flying that morning.