Two men ignored signs warning boaters to stay away from the Milan Steel Dam on the Rock River on Sunday before one died and another was hurt when they rode their personal watercraft over the dam, officials said Monday.

Shane M. Ekin, 40, of Cambridge, Ill., died from presumed drowning. His friend, Anthony K. Sovey, 42, of Cambridge was rescued by firefighters.

Witnesses told authorities the two were operating along the top of the low head dam about 4:30 p.m. and circling within 50 feet of the structure, Chris McCloud of the Illinois Department of Natural Resources said.

They were operating in an area between buoys marked “no boats” and the dam, he said.

Witnesses said the pair rode over the dam once and attempted to ride their watercraft back upstream and over the dam a second time, McCloud said.

Ekin was ejected from his watercraft and was thrown into a boil below the dam, McCloud said. A boil, or “hydraulic roller,” is created when water rolls over the top of a low head dam and over time erodes the river bottom, creating a turbulent, washing machine-like effect in the water, McCloud said.

"Objects can and do become trapped in the boil area because of the current," he said.

Sovey entered the boil on his watercraft and attempted to rescue his friend, McCloud said. Sovey also was ejected from his craft and was able to cling to a partially submerged tree.

Officers and rescue teams from various area departments responded to the scene, including the Illinois Conservation Police, Milan Police Department, Rock Island County Sheriff’s Department, Rock IslandFire Department, Blackhawk Fire Department and Rock Island Arsenal fire crews. A MedForce helicopter also responded to the area.

When rescue crews arrived, only one of the two men could be seen, caught in the turbulence, according to a news release issued by Rock Island Fire Battalion Chief Paul Hoffeditz. Rescue crews had boats in the water but were unable to get to Sovey. Members of the Backwater Gamblers ski team and their boat helped crews float a rescue rope and flotation devices downstream to Sovey, and he was pulled to shore.

Sovey was taken to Trinity Rock Island, where he was treated for minor injuries and release.

Ekin's body was recovered downstream from the dam by crews aboard the Rock Island Arsenal Fire Department's boat.

Both watercraft operators were wearing life jackets, McCloud said, but Ekin was pulled under the water in the boil.

Toxicology tests and an inquest are pending for Ekin, Rock Island County Coroner Brian Gustafson said.

McCloud didn't want to speculate how many people are tempted to disobey the signage, but it has been at least five years since an accident has occurred at the dam, according to online reports.

Illinois Conservation Police continue to investigate.