Pekin police warned in July that the heroin seeping into Tazewell County carried a far greater danger of death than usual for the illegal drug.

Rising fatal overdoses this year, including tragic numbers in September alone, are proving the point.

With a quarter of the year remaining, 14 county residents have already succumbed to drugs, half of them victims of heroin laced with the synthetic drug fentanyl.

That death toll, however, does not yet include five fatalities last month that await final tests to determine their causes.

“That’s a huge spike in one month,” Tazewell County Coroner Jeff Baldi said Friday. He believes he knows what killed the five.

“I would be shocked if most, if not all” of the victims didn’t succumb to fentanyl and heroin, either alone or in combination, Baldi said.

Fentanyl, a pain killer often administered to cancer patients, has increasingly been smuggled from overseas and mixed as a powder with heroin.

“It’s so much cheaper and much more powerful” than heroin, said Dave Briggs, director of the Peoria-area Multi-County Drug Enforcement Group (PMEG).

“We’ve seen that practically all heroin (PMEG has uncovered) has some fentanyl in it,” Briggs said.

That’s likely why drug overdoses, both fatal and non-fatal, have increased in the area, including Tazewell County, he said.

“In Peoria, one or two non-fatal ODs are reported every day, and I’m confident many more go unreported,” Briggs said.

In Pekin this year, police have revived four people overdosing on opiate-related drugs, such as heroin and fentanyl, by applying naloxone, a fast-acting opiate antidote.

Three other victims couldn’t be saved by the city officers, said police Public Information Officer Billie Ingles.

The seven Tazewell County deaths so far this year that were shown to be caused by heroin-fentanyl mixtures are three fewer than last year’s total.

However, if the five outstanding Tazewell death investigations Baldi cited reveal those drugs were their cause, by the year’s end the county could see three times more fentanyl-related deaths than the five recorded between 2009-13, according to coroner records. In 2015, eight heroin-fentanyl deaths took place in Tazewell.

Baldi said the September deaths point to the growing need for addiction victims to realize that any fentanyl in their usual dose of heroin could raise that dose to a fatal level.

Briggs said the growing fatalities “on both sides of the river” make the message clear.

In full force, he said, fentanyl “has arrived in the Peoria area.”

Follow Michael Smothers at Twitter.com/msmotherspekin