SOUTH HAVEN, MI (WHTC) - South Haven Police continue to investigate the circumstances that led to the evacuation of South Haven High School late on Friday morning. A student reported a bomb threat written on a bathroom wall just before 12 Noon, and all inside of the building were taken to nearby Lincoln Elementary School while the structure was thoroughly searched. No explosive device was found, and the all-clear was given around 2:15 PM, shortly before classes were scheduled to be dismissed for the day. The evacuation was conducted without incident. Authorities say that detectives will go over about five hours of surveillance video in an effort to determine who may have been responsible for the threat.