A fighter jet crashed into a field near a Central California air base on Wednesday, killing the two people on board, officials said.

Fresno County deputy coroner Sarah Davis confirmed the deaths with The Associated Press, but did not release other details.

Officials from the Naval Air Station in Lemoore said the F/A-18F Super Hornet aircraft went down shortly after noon in a grassy field about half a mile from the base. Military officials said the two men killed included a pilot and weapons system officer. Officials did not identify the men. Navy spokeswoman Melinda Larson said the crash was under investigation.

The crash happened about a half mile from where a crew for a farm labor contractor was planting tomatoes, and supervisor Jonathan Aguayo described a scene involving black smoke and scattered debris.

"I heard a loud noise, I turned around and saw some smoke," Aguayo said. "It was a big black type of smoke coming off the ground. When my dad and I drove up to take a closer look, we saw some debris in the field, smoldering. One large piece and a bunch of smaller pieces."

Aguayo said he heard the crash but did not see it happen.

The Super Hornets are an advanced version of the single-seat F-18 Hornet, according to the Navy. The jets are used by the military for combat operations and also in the Navy's Blue Angels Flight Demonstration Squadron, which performs aerial shows.

"They're about a $50 million aircraft," said Larson.

Lemoore is about 30 miles south of Fresno. The Naval Air Station, which is home to about 275 jets, is the West Coast hub for the U.S. Pacific Fleet. Its mission is to train and man Strike-Fighter squadrons in the region.