A Spirit Airlines pilot and wife died of overdoses of cocaine and carfentanil, a drug so powerful its primary use is to tranquilize rhinos and elephants, the Montgomery County Coroner’s office confirmed Tuesday. 
 
 >> NEW: ‘Speedball’ use by Centerville pilot not first at Spirit Airlines 
 
 >> EARLIER: Couple’s death may be fentanyl related 
 
 >> MORE: Spirit Airlines pilot’s overdose raises safety questions 
 
 Brian Halye, 36, and Courtney Halye, 34, were found dead in their Centerville home March 16 by their four children who reported the deaths to police. 
 
 The toxicology results confirm what the coroner’s office had previously hinted at: the commercial passenger airline pilot died of an accidental drug overdose. 
 
 The deaths came a week after Brian Halye’s last flight, prompting criticism of the random system used to test pilots. 
 
 Local health officials say the results are consistent with an increasing pattern of people using extremely powerful drugs, and combining potent opioids like fentanyl and carfentanil with cocaine and other drugs. 
 
 Cocaine, opioids deadly mix 
 
 The autopsy does not make clear if the Halyes knew the cocaine they were taking contained carfentanil — a synthetic opioid 100 times stronger than fentanyl and 1,000 times more powerful than morphine. 
 
 It does indicate, however, that both Halyes took the drug by injection. Courtney Halye had needle puncture marks on her right thigh and left wrist, the report shows, while Brian Halye had a single needle puncture mark on his right arm. 
 
 Intentionally injecting cocaine into the body with morphine, heroin or other drugs is known as a “speedball.” 
 
 The powerful concoction has killed celebrities, including former Saturday Night Live star John Belushi more than three decades ago. 
 
 Earlier this month, Hamilton County Coroner Dr. Lakshmi Sammarco warned Cincinnati-area cocaine users that their stashes could be cut with fentanyl or heroin without their knowledge, the Cincinnati Enquirer reported. 
 
 Cuyahoga County Medical Examiner Dr. Thomas Gilson last week told a U.S. Senate subcommittee that he believed drug dealers may be mixing cocaine and fentanyl as a way to increase opioid addiction in the black community, according to The (Cleveland) Plain Dealer. 
 
 A small amount of carfentanil no larger than a grain of salt can kill. In July, Ohio Attorney General Mike DeWine warned police agencies across the state against handling or field testing street drugs that could contain dangerous levels of fentanyl or carfentanil. 
 
 In September, the Drug Enforcement Administration issued a nationwide warning about the health and safety risks of carfentanil that can also resemble powdered cocaine. 
 
 “Just handling it can result in death,” Ken Betz, director of the Montgomery County Coroner’s office, said at the time of the DEA’s warning. 
 
 Airline drug tests questioned 
 
 A Dayton Daily News examination after Halye’s death revealed airline pilots can go years without a drug test. 
 
 The toxicology and autopsy reports do not indicate if Halye had ever used drugs before flying an airplane, but it’s also unknown when Halye was last subjected to a drug test. 
 
 >> MORE: Spirit Airlines pilot may not have been drug tested in years 
 
 “The random nature of testing means that people can in fact get away with things like this,” said Ashley Nunes, a regulatory analyst with the MIT Center for Transportation & Logistics. “It’s certainly concerning to me someone could take cocaine, or have the lack of common sense to take cocaine and fly an airplane.” 
 
 “I suspect he is not the first and will not be the last,” Nunes said. 
 
 Spirit Airlines in March declined to answer the Daily News’ questions about Halye’s last flights, upcoming routes and the dates and results of any drug screenings. 
 
 Airlines officials in March said the pilot, who flew for the airline for nine years, captained his last Spirit Airlines flight six days before the overdose. 
 
 >> MORE: Airline pilots union fought drug testing for decades - and still does 
 
 Cocaine has been a factor in fatal passenger aviation accidents, even when consumed hours before takeoff. 
 
 In January 1988, Continental Air Express 2286 crashed in Colorado, killing the captain and eight others on board. The NTSB later determined the captain’s use of cocaine the night before contributed to the accident, which served to heighten calls for more drug testing. ||||| A Spirit Airlines pilot and his wife found dead by their children in March in their Ohio home overdosed on a lethal combination of cocaine and carfentanil, a powerful derivative of fentanyl often used to tranquilize rhinoceroses and elephants, PEOPLE confirms. 
 
 A spokeswoman for the Montgomery County Coroner’s office tells PEOPLE that Ohio couple Brian and Courtney Halye combined the two potent substances. Their deaths have been ruled accidental. 
 
 After the couple were found dead by their children in their Centerville home, the coroner initially listed the preliminary cause of death as being “consistent with a heroin or fentanyl overdose.” 
 
 Brian, 36, was a pilot for Spirit Airlines. He married Courtney, 34, in 2012. They each had two children from previous relationships — he, two daughters and she, a son and a daughter. The children ranged in age from 9 to 13. 
 
 All of the children have been placed with relatives, according to state officials. 
 
 Facebook 
 
 On March 16, the Halye’s children peeked into their parents’ bedroom after the couple failed to wake them up for school. 
 
 After finding their unresponsive parents, the 13-year-old son called 911 and told the operator, “I just woke up and my two parents are on the floor.” 
 
 The Halyes died one week after Brian Halye’s last flight for the airline, according to officials. 
 
 • Want to keep up with the latest crime coverage? Click here to get breaking crime news, ongoing trial coverage and details of intriguing unsolved cases in the True Crime Newsletter. 
 
 Medical examiners can not say for sure if the Halyes knew the cocaine they were taking had been laced with carfentanil, which is 1,000 times more powerful than morphine. 
 
 But both the husband and wife injected the drug. 
 
 A police incident report from January 2016 alleged that Courtney — a Type 1 diabetic — had a history of drug use. 
 
 The coroner indicates Courtney had needle puncture marks on her right thigh and left wrist, while Brian had a single puncture wound on his right arm. 
 
 In an interview in late March, Courtney’s friend, Monica Camacho, told PEOPLE she thought her friend had defeated her demons. 
 
 “I knew that they had their issues,” Camacho explained, “but I honestly thought that she had things under control. This is so shocking to everyone.” ||||| The couple’s children can be heard on a 911 call after their parents failed to wake them for school. 
 
 "They were very cold," their son told a dispatcher while his three sisters can be heard crying in the background. 
 
 Related: Fentanyl Crisis: Columbus, Ohio Has One Fatal Overdose Per Day 
 
 The son added that they found their parents in bed not breathing and that his sisters described their father’s face as “pale and there was black lines all over his face.” 
 
 Spirit Airlines confirmed Friday of Halye's appointment and said his final flight was March 10. 
 
 "Captain Halye served at the airline for just over nine years," Spirit Airlines said in a statement, noting that they run random drug and alcohol tests on all employees. 
 
 The airlines said anyone who tests positive for drugs is immediately fired. 
 
 Brian and Courtney Halye. 
 
 Although authorities are still investigating, they say the deaths appear to be drug-related and are consistent with a heroin or fentanyl overdose. A toxicology report will take four to six weeks. 
 
 Centerville police added that the deaths appeared to be drug-related because narcotics paraphernalia was found at the scene. 
 
 The director for the Montgomery County Coroner’s Office said heroin overdoses have reached "record numbers for January and February." 
 
 Courtney Halye's mother, Nancy Casey, said her daughter was a Type 1 diabetic, suffered from depression and was on medication. But Casey, 51, believes heroin or drugs were not a persistent problem in the parents' lives, and added that her daughter was well-liked and described her as "a light in the room." 
 
 "I don’t know if they decided they were going to party, or went and they got a hold of this bad stuff going around town," she told NBC News, noting that her daughter should not be characterized as an "addict" or "low-life." 
 
 But she had a bad feeling after she talked to them earlier in the day. 
 
 "I had this dreadful feeling all day," Casey said. "Something was off with her and something was off with him."
– The reason four kids in Ohio woke up to find their parents dead: Brian and Courtney Halye not only injected cocaine, they injected cocaine laced with a tranquilizer so potent it's used on elephants and rhinos. The Montgomery County coroner has concluded that the Halyes used cocaine mixed with carfentanil, a lethal derivative of fentanyl, reports People. The coroner can't say whether the couple knew the cocaine was tainted, only that they injected a fatal dose. The story first made headlines in March not only because their four children, ages 9 to 13, found them on their bedroom floor but because Brian Halye, 36, was a pilot for Spirit Airlines who had flown just a week prior to his death. The Dayton Daily News notes that the deaths are consistent with a pattern of overdoses in which people combine opioids such as fentanyl and its derivatives with cocaine or other drugs. Carfentanil is particularly potent: 100 times more powerful than fentanyl and 1,000 times more powerful than morphine. Last month, the medical examiner in Ohio's Cuyahoga County told a Senate subcommittee that he believed drug dealers were secretly lacing cocaine with fentanyl to increase addiction in the black community, per the Cleveland Plain Dealer. It's not clear when Brian Halye had his last drug test as a pilot. (These 10 states have the biggest drug problems.)