Morongo Valley firefighters were able to save two houses that were threatened by a motorhome fire last night. Captain Andrew Arthen said when they arrived at the fire in the 49400 block of Conejo Road about 5:30, the motorhome was fully involved in flames. It was parked between two homes, and was close to one home. Arthen said firefighters immediately went into a defensive mode to protect the homes and had the fire knocked down in about 15 minutes. He added that the fire in the back of the motorhome was stubborn, though, due to household chemicals, motor oil, and anti-freeze being stored there. And he said that firefighters had a heart-stopping moment when an oxygen bottle inside the RV blew out a hole with “relatively impressive force.” The cause of the fire is as yet undetermined.