A 50th birthday celebration turned deadly when a man and his toddler grandson broke through the ice in a four-wheeler on Lake Andrew near Alexandria, Minn., authorities said Wednesday.

James Minnerath, 50, died after being pulled Tuesday night from the lake near his home and taken to North Memorial Medical Center in Robbinsdale, a hospital spokeswoman said.

His 2½-year-old grandson, Hayden Minnerath, also of Alexandria, remains in Children's Hospital of Minneapolis in critical condition Wednesday, a spokesman said. No further information was released Thursday.

The Douglas County Sheriff's Office said it has yet to determine how long the two had been in the water.

James Minnerath, who turned 50 Tuesday, was marking the milestone by plowing snow in the neighborhood with the specially equipped ATV and riding on the lake with Hayden, the Sheriff's Office said.

Brad Brejcha, a retired sheriff's sergeant who lives along the lake, walked out on the ice about 200 yards from his home on the northeast shore of Lake Andrew and discovered the scene about 8:55 p.m. Tuesday. "I know it didn't look good," he said.

Brejcha said he went out onto the lake after receiving a call from Minnerath's wife, who said her husband and grandson were late returning from an outing on the lake, which is southwest of Alexandria.

Brejcha saw the large hole where the vehicle had broken through and called the Sheriff's Office from his cellphone. He said rescue personnel arrived in "a very short time" and pulled the two from the water.

An ambulance took the man and grandson to the Douglas County Hospital, the Sheriff's Office said. The two were then flown to hospitals in the Twin Cities.

The ATV was recovered from water 18 feet deep.