The US is one of the wealthiest countries in the world. It’s the world’s center of innovation and medical science, yet the country can’t keep their youth from dying. US millennials are now dying at such high rates that it’s driven life expectancy in the country to decline for two years in a row, the first time that’s happened since the early 1960s. The primary cause for the trend is the opioid crisis.

According to recently released data from the US Centers for Disease Control and prevention (CDC), 129 out of every 100,000 25-34 year old US adults died in 2016. Not since 1995, at the height of the HIV/AIDS epidemic, have death rates been so high among this group.

The speed at which death rates are rising among young adults in the US is staggering. In just two years, from 2014 to 2016, the rate at which 25-34 year olds died rose by 19%, from 108 per 100,000 to 129. Death rates also grew quickly for those 15-24 and 35-44 years old. At the same time, the elderly are dying a bit less, and life expectancy for those that reach 75 years old continues to rise slowly.

The explanation for the trends is simple: young Americans are overdosing on drugs, particularly opioids.

In 2010, just 18 out of every 100,000 Americans aged 25-34 died from a drug overdose. By 2014, that rate rose to about 23 in 100,000—then it really took off. From 2014 to 2016 it spiked by 50% to almost 35. The majority of this rise can be accounted for by an increase of deaths from heroin (3.4 to 4.9 for every 100,000), natural and semisynthetic non-heroin opioids like oxycodone (3.8 to 4.4) and, most importantly, synthetic prescription opioids like fentanyl (1.8 to 6.2).

Beginning in the 1990s, doctors began overprescribing opioids for pain management, leading many patients to become addicted. Jay Joshi, the former chairman of the National Pain Foundation, wrote in Quartz that ignorance among physicians and aggressive marketing by opioid manufacturers are primarily to blame for the crisis. Prescription opioids like oxycodone aren’t that dangerous, but patients can become easily addicted and so seek out more potent,cheaper, and conveyors of opiates like heroin and fentanyl, which has led to the recent spike in opioid-related deaths.

Quarterly drug-abuse data from the CDC show that the death rate from drug abuse increased throughout 2016, and there is little evidence in preliminary 2017 data that the situation is improving.

In October 2017, US president Donald Trump declared the opioid epidemic a public health emergency. The move allows some federal funds to be redirected to the crisis, but did not specify an amount. That decision is in the hands of the Republican-controlled Congress. Trump also appointed Kellyanne Conway, the former pollster and campaign strategist, as his “opioid czar,” despite her questionable qualifications for the job. The moves have been seen by some public health experts as a paltry response to the crisis, who say the US will need to spend billions of dollars on addiction treatment, including large investments into medications that help wean addicts off of opioids, in order to solve the problem.