A disturbing mystery in Ohio looks like it might remain a question mark: Why an area of eastern Sandusky County in the northern part of the state has seen so many cases of childhood cancer since 1996. Ohio Health Department officials announced recently that they might soon be ending an investigation into the matter.

Five of 35 cancer-stricken children in the 12-mile wide circle have died, the most recent being a 13-year-old boy earlier this month. Parents and health officials have searched for answers for more than a decade.

Investigators of the child-cancer cluster are expected to issue reports soon, but have long acknowledged they find no commonalities to explain the outbreak. The kids impacted lived in different areas, attended different schools and got their drinking water from different sources.

“We were brutally honest with people from the beginning. We told them we may never find the cause,” said Robert Indian, who heads the Ohio health department’s cancer-control program. “The track record across the country is you rarely find the cause of something like this. It gets horribly complex.”