The Ventura County Sheriff’s Department is warning the public after its bomb squad responded to a call at an Ojai home last week when a concerned citizen brought home a Navy MK25 phosphorus marine marker found on the beach. An MK25 marine marker is an aerially or manually deployed pyrotechnic device that creates both smoke and flame to mark a specific reference point on the water’s surface, according to the U.S. Army. The citizen noticed the marker at the waterline while walking on the beach and, fearing for the safety of other beachgoers, decided to take the marker home and...