Seventeen people, some of them children, were killed Thursday evening when a duck boat capsized and sank in severe weather near the tourist mecca of Branson, Missouri. Seven people have reportedly been hospitalized after the incident on Table Rock Lake. Four of the 17 had been missing, but were found dead Friday, NBC New York reports. A witness aboard a nearby vessel captured video of two of the duck boats—amphibious vehicles that can also be driven on land—on the lake before one of them capsized during stormy weather. The video shows the boats rocking as large waves slam into them. Stone County Sheriff Doug Rader said an off-duty deputy from his department had been at the scene when the boat went under. He credited the deputy with rescuing some of the passengers. “We do have some people still missing so this is going to be all night into the morning we’re going to be working on this,” the sheriff said.