SAN MARCOS, Calif. – Black smoke from a fire at a recreation vehicle business in San Marcos was seen for miles Sunday afternoon.
The three-alarm fire started around 4 p.m. at the Holland RV Center, near San Marcos Boulevard across from Home Depot.
Some witnesses told FOX 5, they heard an explosion at 200 Travelers Way near state Route 78. Soon after, a SIG Alert was issued by CalTrans.
“Obviously, all the RVs have propane tanks. We don’t know exactly what exploded – that’s what we’re guessing right now," said San Marcos Fire Chief Brett Van Wey.
The fire started in the dealership's service center, which was closed and unoccupied.
“I feel sorry for the people who had their motor homes in the service department – because they’re probably gone," said Carlos Royal, who watched the fire from across the street.
About 70 firefighters contained the fire to the service center and kept it from spreading to the sales center.
It was unknown what caused the explosion. No one was hurt.
Some firefighters and investigators were expected to stay on-scene through the night.
Something's burning in San Marcos. pic.twitter.com/7qWFBJUIH0
— Bill Rote (@billrote) October 11, 2015
This is a developing story and will be updated as information becomes available.