Authorities now say alcohol played a significant role in a Father’s Day river outing that turned deadly in Des Moines. Two pleasure boats collided Sunday night on the Des Moines River and both boat operators are now charged with boating while intoxicated.

The D.N.R. says four people were thrown into the water, two from each boat, including 49-year-old Kelly Starrett — who was killed. The West Des Moines man was attending a family gathering and his granddaughter was with him on the boat.

His brother, 46-year-old Tony Starrett of Des Moines, is among the two charged with drunken boating. Fifty-four-year-old Steven Mayo, of Des Moines, is also charged with Boating While Intoxicated.

Two of the passengers were injured. Both were treated at a hospital and released.