Three of 18 people who overdosed on heroin  Sunday into Monday in Washington County died, investigators said. 

The cases were reported in several areas, including Donora, Amwell, Canonsburg, Houston and Washington.

Seventeen of the 18 cases occurred Sunday night.

Washington Health System treated the majority of those who overdosed.“To see a bunch like that is very uncommon. Usually we see one or two a week,” said Dr. Tony Aprea, the medical director of Washington Health System.

Canonsburg Police Chief Alexander Coghill said his officers were able to save one victim with the use of Narcan.

“(It) revived her almost instantly. Without that, she would’ve been left there and probably would’ve died,” he said.

Washington County emergency dispatchers confirmed that the most recent overdose occurred Monday evening at a Walgreens in Washington, bringing the total to 18 over the course of 24 hours. Dispatchers said the woman was revived, but her condition was not released.

Coghill told Channel 11 that the overdoses were likely caused by heroin, with bad batches possibly coming from either Colombia or Mexico.

Channel 11’s Melanie Gillespie reported that police departments are sending reports to the District Attorney’s Office to determine any connections among the cases.

At the end of July, emergency responders in Washington County received training in the use of Narcan, a drug that can reverse the effects of a heroin overdose. A state grant made Narcan available to police departments and fire stations throughout the county.

• Officers from local departments get training on how to use heroin antidote

In the spring, a string of overdoses in the Pittsburgh area stemmed from a bad batch of heroin that investigators determined contained fentanyl.

• 10 heroin overdoses in 24 hours; Pittsburgh officials fear could only be beginning