Duck boats: What NTSB says

July’s horrific sinking of a “Ride the Ducks” boat was similar to another tragedy in 1999 in Arkansas.

Seventeen people were killed in the accident in Branson, Missouri, including nine members of one family.

The duck boats operate on land and in water.

According to the NTSB, which is still investigating the July incident, like the Arkansas tragedy, the Missouri duck boat had a hard canopy over its top.

The NTSB said in 1999 that the canopy roof contributed to loss of life. When the boat sinks, passengers, if wearing life jackets, float to the canopy and are pinned there. In the 1999 accident where 13 of 21 passengers drowned, investigators found the bodies of four people pinned at the canopy.