Oceanside residents who live near Camp Pendleton said they heard several loud blasts two to three hours before they saw heavy smoke approaching their neighborhoods.
"It's very common here, but on Monday after hearing several blasts, we heard one loud blast and our home shook," Oceanside resident Lene Olson said. "That was the last thing we heard until we smelled the smoke a few hours later."
The fire burned about 3,980 acres and was 75 percent contained Wednesday.
The cause of the fire is still under investigation, but the fire was not started as a result of any type of military training, Camp Pendleton commanding officer Jim Seaton said.
The day after the fire broke out, several people reported that they heard some type of training going on, which they found surprising due to the red-flag warning.
Marines who spoke on the condition of anonymity said the Juliet training area, which is where the fire is said to have started, never allows live-fire training.
Another brush fire on Camp Pendleton Wednesday that scorched more than 100 acres and shutdown Interstate 5 was ignited when a mower’s blade struck a rock Tuesday, officials said. Sparks ignited brush near Las Pulgas Road at Camp Pendleton. Firefighters contained the fire less than two hours later.