It's known on the street as China White, Dance Fever, Murder 8 and Jackpot.

An Ohio addiction doctor calls it "terrifying," a county coroner labels it "overwhelming" and the Columbus health commissioner says it's "very sobering."

Many Ohioans know the powerful painkiller fentanyl as a cold-blooded killer that preys indiscriminately on addicts: rich and poor, urban and rural, male and female.

And most of them never knew what killed them.

Fentanyl, a synthetic opioid, is cheap, simple to make, easy to buy and 50 times more powerful than heroin. It is rapidly eclipsing heroin as Ohio's most vicious killer. It is taking at least one person a day in Franklin County alone.

All drug overdoses statewide are soaring, but mostly because of fentanyl. When the tally is complete, drug overdose deaths in general likely will top 4,000 in Ohio for 2016 — a 30 percent increase over 2015.

Beth Carey isn't sure what killed her identical twin sister, Chrystina Carey, on Feb. 22, 2013. The Marion woman's death certificate lists "morphine," the drug that fentanyl, heroin and similar drugs break down into once ingested by a person. Only recently have coroners begun testing specifically for fentanyl and the even more powerful carfentanil, an animal tranquilizer.

The twins were born Feb. 28, 1982. They barely knew their mother, who was an addict and prostitute. She went out for a pack of cigarettes and never returned, leaving her daughters to be raised by their grandmother. The twins grew up inseparable, bonded by the absence of their mother and a father they never knew.

Beth Carey says she didn't use drugs, but her sister did, "starting with ecstasy then oxycontin. She moved on to heroin and was probably using drugs for eight years."

Miraculously, Chrystina's baby, Jazlen Harden, was born healthy even though her mother used heroin throughout her pregnancy. Chrystina overdosed multiple times, but emergency responders brought her back with naloxone, a drug that saves people from overdoses.

Beth Carey said her sister's addiction was "bigger than us. She lived by doing drugs."

After spending several months in jail, and being forced to kick the drug habit, Chrystina shot up shortly after being released. 

It was just a few days before their 31st birthday when Beth got the call from Marion police. Her sister was dead.

"I had seen her decline. I knew her struggle and demons with her addiction," she said.

"I was no longer a twin."

Beth Carey is now raising Jazlen, who is 5. Beth tells her she has two mommies, including her "mommy in the sky."

"Soccer moms ...

who are heroin addicts"

The National Institute on Drug Abuse says that legal fentanyl — used for severe pain — is available via injection, a skin patch, lozenges or a lollipop. However, illegally produced fentanyl comes as a powder or spiked on blotter paper. Dealers commonly mix fentanyl with heroin, marijuana and other drugs, in part because fentanyl is cheap.

Treatment is available, but fentanyl is so addictive and deadly that many "people aren’t making it to treatment,” said Shawn D Holt, president and chief executive officer at Maryhaven, a Columbus drug and alcohol treatment center. Maryhaven treated 11,000 people in central Ohio last year, and 80 percent were addicted to opioids.

Holt said he recently asked his staff for the relapse rate for fentanyl users. 

"I was told there was none because people are dying," he said.

Stories from across Ohio about overdose deaths are legion — and often the users' children suffer the consequences:

• Annabella Sagstetter, 14 months old, died in 2015 after her mother brought her into a Hilltop drug house strapped in a car seat. She was somehow exposed to a lethal combination of heroin and fentanyl. "I will never forgive myself," Erica Barley of Reynoldsburg told a Franklin County judge who sentenced her to five years in prison for involuntary manslaughter. "Deep into my addiction, I thought she was safest with me. I never thought this could happen. Now, after being sober, I know that bringing her there put her in danger and caused the worst possible tragedy."

• Courtney A. Halye and Brian Halye died in March of suspected drug overdoses involving fentanyl or heroin. Their bodies were found by their four children in the bedroom of their Centerville home, south of Dayton. Mr. Halye was an airline pilot.

• Denise N.  Dickinson and Kyle R. Black were sentenced to prison on involuntary manslaughter charges in the death of their 11-month-old son, Dominic. The baby died in 2015 of what turned out to be “acute intoxication of heroin and fentanyl.” The child somehow ingested the drug while in bed with his parents, who had used the heroin-fentanyl combination.

Columbus firefighters on the front lines of the epidemic are administering naloxone, also known as Narcan, eight or nine times a day on average. That's double the rate of just a year ago — a spike they attribute directly to fentanyl.

Medics are bringing people back after finding them unconscious and not breathing in cars along the side of the road, in parking lots and in public restrooms. Overdoses have become routine on the Hilltop, the South Side and in the Linden neighborhoods in particular. The berm of Route 23 is a frequent stop for drug users from southern Ohio who come to Columbus for a fix, then overdose after they pull over to use drugs on the way home.

"It's not just a poor, inner-city thing. It's in very nice neighborhoods, too. There are soccer moms in Dublin who are heroin addicts," said Columbus Fire Capt. Scott Krummel. 

With fentanyl, "they go into a quicker, deeper overdose, and it takes more and more (Narcan) to get them out of it," Krummel said. Last September, when Columbus was hit with a record number of overdoses, medics administered, on average, 17 doses of naloxone to 10 individuals each day. Most needed more than one dose to start breathing again.

"Overdose deaths have nearly doubled (in recent years). It's very sobering," said Columbus Health Commissioner Teresa Long. She is encouraging all citizens to carry Narcan, which is available without a prescription at most pharmacies, to potentially save a life. "People can overdose anywhere," she said.

"We see pain in every death ..."

Dr. Jon Sprague, a professor at Bowling Green State University and director of Attorney General Mike DeWine's Center for the Future of Forensic Sciences, said fentanyl has been around since 1960 when it was invented as a painkiller for use in cardiac surgery.

"It's a very potent pain-relieving substance that unfortunately produces euphoria," he said. Like other opioids, Fentanyl reduces the pain signals from the brain while also stimulating the release of dopamine, the chemical that creates a sense of euphoria.

Fentanyl's potency can cause respiratory depression, coma and death. Even a dose of micrograms, the size of a grain of salt, can be fatal. That is why law enforcement, prosecutors and lab technicians now wear protective hazardous-materials suits when handling it.

Sprague said the drug is cheap to make, with ingredients costing $358 producing an amount of fentanyl that has a street value of $18,000.

Dr. Kent Harshbarger, the Montgomery County coroner, said 85 percent of people who die of overdoses have fentanyl in their systems, sometimes multiple kinds or "analogs" of fentanyl. There were 259 fatal drug overdoses in Montgomery County in 2015, 349 last year and more than 200 in the first four months of this year.

"I don't think the users are going into a dealer and saying, 'Give me fentanyl.' They want a bigger hit, a quicker high."

Harshbarger's office covers 30 counties, meaning his technicians are constantly performing autopsies on overdose victims.

"We see pain in every death, but there is no time anymore to decompress. We're running from case to case, scene to scene, tragedy to tragedy. ... It's overwhelming to see the same story over and over."

Dr. Shawn Ryan, president of Brightview, a Cincinnati addiction-treatment center, and president of the Ohio Society of Addiction Medicine, said 90 percent of the patients he treats for opioid disorders have recently used fentanyl.

Using a combination of medical, psychological and social treatments, Ryan said, his patients have a 70 percent chance of kicking the drug habit.

The rush of fentanyl has "demonstrated the inadequacy of our treatment system," Ryan said.

Orman Hall, an analyst with the Ohio High Intensity Drug Trafficking Area task force, said fentanyl's potency makes it go further with drug dealers. A kilogram (2.2 pounds) of heroin breaks down into 10,000 doses on the street, but the same amount of fentanyl would make 500,000 doses.

A key to fentanyl's addictive nature, Hall said, is the relatively short duration of its euphoric effects. A heroin user can stay high on a single dose for an average of three hours, but the high from a dose of fentanyl lasts only about 45 minutes. A shorter, more powerful high means the addictive craving returns far more often, resulting in more trips to the drug dealer.

Fentanyl alone killed more than 1,000 Ohioans last year, and carfentanil was responsible for 174 overdoses in Cincinnati during a six-day span, according to U.S. Sen. Rob Portman, who has introduced a bill that aims to keep the drug from flooding in from other countries, such as China and India. Many times, it's shipped through Canada into the United States. 

The Ohio Republican said that private carriers such as UPS and FedEx require electronic advance data — including who and where a package is coming from, who it’s going to, where it’s going and what’s in it — but the U.S. Postal Service does not.

His bill, co-sponsored by Democratic U.S. Sen. Sherrod Brown and sponsored in the House by U.S. Rep. Pat Tiberi, R-Genoa Township, would require the Postal Service to also require electronic advance data, ideally enabling Customs and Border Patrol to target illegal packages. Brown, meanwhile, has introduced a second bill that would provide $15 million to help give Customs and Border Patrol additional tools to detect fentanyl that's being shipped in from overseas.

“It will put a huge dent into it and help a lot,” said Tiberi of the Portman bill. “It’s a piece of a tool to deal with drug traffickers.”

Beyond that is a need for more people to understand the deadly consequences of even getting near fentanyl.

“If people knew where these drugs were really coming from, they’d never, ever use these things,” said Peter Pitts, a former Food and Drug Administration associate commissioner who is now president and co-founder of the Center for Medicine in the Public Interest.

Dispatch Washington Reporter Jessica Wehrman contributed to this story.