About 100 people fishing on a frozen lake in Minnesota were rescued after a large chunk of the ice broke off, leaving them stranded.Emergency dispatchers received a 911 call just after 11:30 a.m. Monday from people who were fishing on Upper Red Lake in northern Beltrami County, according to a news release from the Beltrami County Sheriff's Office.Once first responders arrived, they estimated the fishermen had drifted up to 30 yards into open water following the breakage, according to the sheriff's office.A fisherman named Shane from North Woods Fish Houses in Beltrami County said in a video posted to Facebook that "a pretty big crack" opened up from east to west.Northern Minnesota had a cold snap before the Thanksgiving holiday, when many lakes produced ice cover."