Marines cut through concrete slabs with a jackhammer during urban search and rescue training at Treasure Island, Oct. 7, 2015, as part of San Francisco Fleet Week 2015. The event featured demonstrations and hands-on training with tools commonly used for rescue missions during disaster relief. - Marines cut through concrete slabs with a jackhammer during urban search and rescue training at Treasure Island, Oct. 7, 2015, as part of San Francisco Fleet Week 2015. The event featured demonstrations and hands-on training with tools commonly used for rescue missions during disaster relief.