The Iowa Department of Natural Resources is leading the investigation into a fatal boating collision Thursday night on the Mississippi River. It happened shortly after 9 p.m. in Schmidt Harbor near Dubuque.

Forty-five-year-old James Sutton of Maquoketa was killed when the boat he was operating was hit by another boat operated by 38-year-old Kent Hoffman of Galena, Illinois. D.N.R. spokesperson Kevin Baskins says the Hoffman boat went over top of Sutton’s vessel.

Investigators believe Sutton’s boat was not moving at the time. Hoffman was not injured. A passenger in Sutton’s boat, 47-year-old Lori Fey of Maquoketa, was injured – but not seriously, according to Baskins. He says it’s unclear what led to the collision, but speed may’ve been a factor.

“Certainly, trying to determine the speeds that might have been involved will be a key part of the investigation,” Baskins said. There’s no word yet if alcohol was a factor in the crash.

“At this point, we’re still uncertain,” Baskins said about the possibility of alcohol being involved. A number of witnesses to the collision are being interviewed. The incident occurred after dark, adding to the difficulty of the investigation. It’s the fourth boating related fatality in Iowa this year.

Baskins says boating crashes are always difficult to investigate as you don’t have the physicall evidence such as skid marks. He says in a boating accident parts of the boat can fall into the water and be hard to recover to aid in the investigation.