NAVARRE, Fla. (AP) — Fog and mist are hampering the search for seven Marines and four soldiers presumed to have died when a Black Hawk helicopter crashed over water in Florida.

The helicopter crashed Tuesday night in the Santa Rosa Sound along the Florida Panhandle during a training exercise.

Hundreds of people attended a solemn candlelit vigil Wednesday night on a pier jutting into the Gulf of Mexico.

The emotional ceremony capped a difficult day for communities with strong ties to the military. There are several significant military bases in the area.

Military officials haven't said what caused the crash, but the weather was bad enough for another helicopter on the training run to return to land.

The Marines on board were based at Camp Lejeune, North Carolina. The soldiers were from Hammond, Louisiana.