According to a report issued by the National Transportation Safety Board in 1999, a canopy used on a duck boat that sank near Hot Springs, Arkansas, contributed to the deaths of several people trapped inside the sinking vessel.In several eyewitness videos, a similar canopy can be seen on the duck boat that sank and killed 17 people on Table Rock Lake in Branson, Missouri, Thursday.On May 1, 1999, the duck boat Miss Majestic sank during a tour of Lake Hamilton near Hot Springs. Of the 21 people on board, 13 passengers, including three children died.According to NTSB investigators, several factors contributed to the sinking. They discovered water first entered the boat through a gap between the driveshaft and its housing because a clamp wasn't adequately tightened by mechanics. The pump designed to pump water out of the boat wasn't working. The maintenance wasn't adequate and the Coast Guard's inspection program wasn't rigorous enough.The report also concluded the canopy trapped several people as the boat sank: "The canopy on the Miss Majestic was a major impediment to the survival of the passengers." Of the 13 killed, seven were found inside the main passenger compartment of the boat, including four people floating in the canopy.The report also concluded life jackets could have been more dangerous to those trapped inside because they would have been unable to swim downward away from the canopy.According to the report: "If the vehicle had not had a canopy, the passengers would not have had a barrier to vertical escape. They would not have been trapped inside the vehicle, and fewer passengers might have been killed."The NTSB suggested removing canopies on duck boats following the incident, but the agency cannot enact regulations.You can read the entire NTSB report from the 1999 incident here.