For years, car accidents topped the list as the leading cause of accidental death in the United States. According to a report from the National Safety Council, however, scientists reveal that there is a new killer facing Americans, claiming more lives than any other accidental cause of death.

NPR reports that the growing problem of opioid painkiller abuse has been the leading contributor to accidental deaths in recent years. The NSC reveals that over 136,000 people died accidentally in 2014, the highest level on record. The number of accidental deaths in 2014 increased 4.2 percent over 2013 levels and 15.5 percent over the preceding decade.

Overdoses from opioid painkillers claimed more than 42,000 lives in 2014. Categorized as a “poisoning” death, this number is nearly quadruple what it was in 1998. By contrast, deaths from motor vehicle accidents have been steadily declining since the 1980’s, with 35,398 reported in 2014.

The shift in trends can be attributed largely to consumer protection policies that resulted in the addition of seatbelts and airbags to all new vehicles produced since the 1980’s, as well as tighter licensing laws for teen drivers. According to Ken Kolosh, the statistics manager for the National Safety Council, “Far fewer teenagers and young adults are dying on the roads than they were in 1981.”

While improved safety measures has significantly reduced the number of deaths from auto accidents, regulators struggle to reconcile the risks posed by opioid painkillers with the benefits they provide to people in pain, as well as the massive profits generated by the drugs. The likelihood of addiction to these medications is dangerously high, and many people with chronic pain who can no longer afford the drugs turn to cheaper and more dangerous alternatives like heroin.

Further information from the National Safety Council can be found here.