The first call came at 7.33pm local time: two people had overdosed on heroin in a home just a few hundred metres from the station where firefighters were awaiting their nightly round of drug emergencies.
By 8.42 - 69 minutes after the first report - a county of a little more than 200,000 people had recorded eight overdoses, all believed to be caused by heroin.
There would be a total of 16 overdoses in 24 hours and 25 over two days. Three people died. Many of the others were saved by a recent decision to equip every first responder with the fast-acting antidote naloxone.
The toll was not from a supply of heroin that had been poisoned on its journey from South America to southwestern Pennsylvania. Nor was there an isolated party where careless junkies miscalculated the amount of heroin they could handle. It was simply an extreme example of what communities in parts of the United States are enduring as the heroin epidemic rages on.
"It's absolutely insane. This is nuts," said District Attorney Eugene Vittone, a former paramedic who is trying to hold back the tide of drugs washing across Washington County, a Rust Belt community 48km south of Pittsburgh.