WAYZATA — Authorities have identified a Maple Grove man and his grandmother who drowned when their car broke through the ice on Lake Minnetonka.

The Hennepin County medical examiner says 31-year-old Harland Dietrich and 87-year-old Mary Ann Haram were both pronounced dead just after 7 p.m. Saturday at Hennepin County Medical Center.

Dispatchers got a call just before 2:30 p.m. Saturday from a man who said his car was sinking in Lake Minnetonka, under the Gray’s Bay Bridge in a channel of the lake. Dietrich and Haram were unconscious when divers recovered them.

Authorities say it’s extremely dangerous to drive or walk on channels and pressure ridges on Minnetonka. Fourteen vehicles have broken through the ice there this winter. All but one of the accidents happened on channels or pressure ridges.