The boys were last seen playing Sunday afternoon outside a home in Rice Township a few blocks from the river. Authorities received a call just before 1:30 p.m. that the boys had fallen through the ice.
Sandusky County Sheriff Kyle Overmyer says divers found the boys in the river and they were taken to local hospitals, where they were pronounced dead.
Overmyer has identified the boys as 8-year-old Jay'Den Taylor-Everett, his brother, 9-year-old Da'Vontae Everett, and 11-year-old Rafel Villanueva, all of Fremont, Ohio.
It was not immediately clear what led the boys to walk onto the ice. The sheriff's office is investigating.