7-Year-Old Girl Is Sole Survivor of Fishing Boat Accident That Killed Her Grandfather and Great-Grandfather

A 7-year-old girl is the sole survivor of a boat accident that claimed the lives of two of her family members during a fishing trip.

The girl was in the vessel with her grandfather and great-grandfather when it capsized at LaSalle Lake State Fish and Wildlife Area, Ill. on Sunday, Aug. 18, per a press release from the Illinois Conservation Police.

Clarence B. Royster, 80, Clarence B. Royster III, 53, and the 7-year-old girl were on a 17-foot Crestliner fishing boat when it began to capsize. The LaSalle County Coroner publicly identified the men on Tuesday, Aug. 20. Police said that neither of the men were wearing a life jacket, but the child was, per the release.

The incident occurred at the 2,000-acre manmade lake, LaSalle Lake, which is located near Marseilles, Ill. — approximately 80 miles southwest of Chicago.

Just after noon, authorities received a 911 call about a “distressed boater” at the lake. Once the police arrived, they found the young girl with park visitors on the shoreline. The visitors assisted the child and helped her contact her mother and grandmother, according to the release.

The authorities were joined by additional police and first responders from numerous agencies to search for the two men. At 7:45 p.m. on Sunday evening, the men’s bodies were recovered. The LaSalle County coroner pronounced them dead at the scene, per the press release.

It remains undetermined as to what caused the boat to capsize, police said. LaSalle County Coroner’s Office and Illinois State Conservation Police are conducting an investigation into the incident.

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer​​, from celebrity news to compelling human interest stories. 

A representative for Illinois Conservation Police did not immediately respond to PEOPLE’s request for additional information on Tuesday.