Dangerous conditions led authorities to suspend the search Sunday for a snowmobiler they believe broke through the ice and was swept down a remote part of the St. Croix River.

Authorities got a 911 call just after 6:30 p.m. Saturday that a snowmobiler had broken through the ice on the river in the St. Croix River National Scenic Waterway on the Minnesota-Wisconsin border, the Pine County Sheriff's Office said in a news release.

Two other snowmobilers told authorities they were riding on the frozen river in the dark when the victim hit a large patch of open water. He was thrown from his machine and disappeared.

Authorities believe he may have been swept downstream and under the ice pack, according to the release. Responders found a partially submerged snowmobile on the edge of a large open area of turbulent water, but no sign of the victim.

It was too dangerous for responders to enter the water, but they searched on foot, by snowmobile and helicopter Saturday night. The responders included deputies from the Pine and Burnett County, Wis., sheriff's departments and personnel from the Pine City fire department and National Park Service.

The search resumed Sunday morning, but Chief Deputy Steven Blackwell told WCCO Radio the search had to be suspended about 12:30 p.m. due to dangerous conditions that included turbulent water and rough terrain.

The victim's name was withheld pending notification of relatives.

It was one of two apparently fatal snowmobile accidents on the St. Croix River on Saturday.

Downstream, in Bayport, a 22-year-old snowmobiler died after going through the ice about noon Saturday near the Xcel Energy Allen S. King power plant. The Washington County Sheriff's Office identified the snowmobiler as Billy Meister, of Stillwater.

Meister was pulled from the water about 20 minutes after he went through the ice and taken to a hospital, where he was pronounced dead.

He worked at his family's Stillwater restaurant, Meisters Bar and Grill.

Also Saturday, a snowmobiler suffered life-threatening injuries in Pine County when he apparently struck a partially submerged island and was thrown from his snowmobile on Pokegama Lake about 9:15 p.m., the sheriff's office said. Authorities did not know the condition of the victim on Sunday.

Earlier this month, Harland Dietrich, 31, and his grandmother, Mary Ann Haram, 87, were trapped underwater and died when Dietrich's car broke through thin ice on a channel on Lake Minnetonka.

Two weeks earlier, 8-month-old Tabitha Markle died when her family's SUV broke through another channel on Lake Minnetonka. Her father, who was driving and intoxicated, was charged with felony criminal vehicular homicide.

Staff writer David Chanen contributed to this report.