Authorities in the Cincinnati area say an unprecedented spike of overdoses seems to be leveling off after a stunning wave that exhausted first responders.

Newtown Police Chief Thomas Synan (SEYE'-nun) heads the Hamilton County Drug Coalition task force. He says drug overdoses dropped to 10 to 15 a day over the weekend. Just Friday, emergency rooms reported 174 overdose cases over six days, for an average of 29 per day, although Synan says some likely were not from heroin.

He says authorities have seized samples of the heroin being sold for testing, hoping to determine the source. They suspect it was mixed with another drug such as a powerful painkiller or animal tranquilizer.

Communities in the neighboring states of Indiana, Kentucky and West Virginia also saw overdose spikes last week.