Video from a nearby business shows the moment the front of a building collapsed Wednesday at a strip mall, trapping six people behind a wall debris. LA County fire officials say a 50-foot section in front of Beauty De Color Salon fell for unknown reasons around 4 p.m. People were trapped in an adjacent dry cleaners business and the salon east of Los Angeles. Video from another business at the strip mall shows the front of the salon drop in a heap of dust and debris. A person can be seen nearly walking under the facade just as it falls. “It felt like an earthquake," witness Justin Han said. "Started hearing squeaky noises. Suddenly the roof collapsed. Everybody started running to the back.” Structural engineers are expected Thursday to help determine what caused the collapse and when repairs can begin. Theressa Nguyen, the owner of Beauty De Color Salon was among six people rescued by firefighters.