Public health officials in Louisville are warning of a spike in heroin overdoses in the city.

Officials at hospitals and emergency rooms around Louisville confirmed at least 28 suspected heroin overdose cases on Tuesday. The Jefferson County Coroner’s Office confirmed that one person had died of a heroin overdose.

A spokesperson said that University of Louisville Hospital saw 11 overdose cases Tuesday night. Norton saw nine cases, a spokesman said. And both Jewish Hospital and Sts. Mary & Elizabeth Hospital also saw a spike in suspected overdose cases during the past several days, spokespeople there confirmed.

Dr. Robert Couch, an emergency physician at Norton, said he saw eight overdose patients within five hours.

He calls it a “public health emergency,” saying the heroin on the street seems to be unusually potent. He says patients taking what would usually be a small amount are losing consciousness.

Couch says larger doses of naloxone, a widely available overdose antidote that many first responders carry, are needed to reverse the drug’s effect.

The announcement comes after recent overdose spikes in communities in the neighboring states of Indiana, Ohio and West Virginia.