Pilot believed dead in Florida military crash

FORT PIERCE, Fla. (CNN) -- The pilot of a military jet that crashed near here Tuesday is believed to be dead, rescue officials said.

"The biggest piece of metal we've found so far is about the size of human hand," said St. Lucie County Sheriff Ken Mascara.

He said the impact left a 15-foot-deep crater in the middle of a pasture on a large ranch, and debris is scattered for about a quarter of a mile beyond the crash site, which is about 20 feet long and 20 feet wide. The crash occurred about 25 miles west of Fort Pierce.

In Washington, a U.S. Navy spokesman Commander Hal Pittman said it is believed that a F/A-18 Hornet is the fighter jet now listed as "overdue" at the Naval Air Station at Key West, Fla. Only the pilot was onboard the plane.

He said the F/A-18 was flying from Oceana Naval Air Station in Virginia.

No survivors were found in the wreckage, said St. Lucie County Fire Department spokesman Capt. Tom Whitley.

He said police have secured the debris field at the site of the crash until military officials arrive to investigate. The crash was reported around 10:30 ET, he said.

Mascara said an aviation unit was sent up to search the ground for parachutes of survivors but none were found.

CNN National Security Producer Chris Plante contributed to this report