Hamilton County's civil-defense sirens date to the world wars, when they were more commonly used as air raids to warn about enemy attack.
Today, they're most often used to warn the public about severe weather, although authorities can sound them to alert residents to any wide-reaching emergency, said Don Maccarone, director of the Hamilton County Emergency Management Agency. They're typically used only three to four times a year.
The county has 175 sirens, more than 60 of them in Cincinnati, Mr. Maccarone said. The sirens cannot be selectively activated; if one sounds, they all sound. Only St. Bernard and Norwood are able to control their own sirens.
That system should be changed by early next year, when authorities aim to have new technology that will allow them to sound individual sirens by radio control, Mr. Maccarone said.
Each city will pick up the $3,500-per-siren cost to convert to radio control, he said.
