Over the last decade, nearly 21 million prescription painkillers have been shipped to a tiny town in West Virginia, a state where more people have overdosed on opioids and died than in any other in the nation.

The House Energy and Commerce Committee, which has been investigating the opioid epidemic, revealed that 20.8 million hydrocodone and oxycodone pills have been delivered to Williamson, W.Va., a town with a community college, a rail yard – and fewer than 3,200 residents, according to the most recent Census figures.

That's more than 6,500 pills per person – though not all of the painkillers stayed in Williamson.

As the Charleston Gazette-Mail reported, committee leaders sent letters to two regional drug distributors, asking why the companies oversupplied this town, among others, with painkillers.

"These numbers are outrageous, and we will get to the bottom of how this destruction was able to be unleashed across West Virginia," Reps. Greg Walden (R., Ore.) and Frank Pallone Jr. (D., N.J.) said in a statement, according to the Gazette-Mail. Walden is chairman of the committee, and Pallone is the ranking Democrat.

Attorney General Jeff Sessions on Tuesday announced a nationwide crackdown on pharmacies and prescribers that are oversupplying opioids amid a deadly epidemic sweeping the United States. A 2016 Washington Post investigation found that a number of drug companies and pharmacies have failed to report narcotics flooding small towns.

A 2016 investigation by the Gazette-Mail shed light on the issue in West Virginia – and the Post reported last year that a new legal front has opened in the war against the opioid crisis, as attorneys in the state began to file federal lawsuits targeting some of the nation's largest distributors of prescription painkillers. The lawsuits, filed on behalf of various West Virginia counties, are seeking billions of dollars in reimbursements for the devastation the drugs have caused in communities across the country.

In the letters, dated Jan. 26, the congressional committee noted that between 2006 and 2016, drug distributors shipped large quantities of hydrocodone and oxycodone to two pharmacies in Williamson, which is in Mingo County, on the Kentucky border.

During that time, Tug Valley Pharmacy received more than 10.2 million pills and Hurley Drug Co. received more than 10.5 million pills, according to Drug Enforcement Administration data that was provided to the committee.

The pharmacies are 0.2 miles apart.

Tug Valley Pharmacy declined to comment. Nicole McNamee, the owner of Hurley Drug Co., said that while the numbers may seem disproportionate, the two pharmacies have to cover a large service area: They are, she said, the only drugstores in Williamson, the county seat and the hub for surrounding rural communities, including parts of nearby Kentucky.

"All the prescriptions we filled were legal prescriptions written by a licensed provider," she said Wednesday.

The committee said in a letter to distributor Miami-Luken that from 2008 to 2015, the company had supplied more than half of all the prescription pain pills shipped to Tug Valley Pharmacy.

And distributor H.D. Smith, the committee said, provided the pharmacies with nearly 5 million pills between 2007 and 2008. "West Virginia court documents suggest that at one point, H.D. Smith provided the two pharmacies with 39,000 hydrocodone pills over a two-day period in October 2007," committee members wrote in the letter to the company.

Richard Blake, an attorney representing Ohio-based Miami-Luken, said the committee has questions about distributions from a number of drug companies. He said Miami-Luken, a small supplier that ships to parts of Kentucky, Ohio, and West Virginia, is "fully cooperating" with the committee, "providing them with all the information they're requesting."

Asked about whether the number of pain pills sent to Williamson were representative of shipments to other towns, Blake said he did not have that data on hand.

H.D. Smith, in a statement to the Post, said the company in Springfield, Ill., "operates with stringent protection of our nation's healthcare supply chain. The company works with its upstream manufacturing and downstream pharmacy partners to guard the integrity of the supply chain, and to improve patient outcomes. The team at H.D. Smith will review the letter and will respond as necessary."

The House committee also noted extensive shipments from the two companies to pharmacies elsewhere in West Virginia, including Beckley, Kermit, Mount Gay-Shamrock, and Oceana.

"The committee's bipartisan investigation continues to identify systemic issues with the inordinate number of opioids distributed to small town pharmacies," Walden and Pallone said in their statement. "The volume appears to be far in excess of the number of opioids that a pharmacy in that local area would be expected to receive."

In 2016, more than 42,000 people in the United States overdosed on opioids and died; 40 percent of those deaths were attributed to prescription painkillers, according to data from the Centers for Disease Control and Prevention. West Virginia, which has the highest opioid overdose rate in the nation, recorded 52 deaths per 100,000 people that year, according to the data.

Hydrocodone and oxycodone are semisynthetic opioids used to treat pain. But hydrocodone (commonly known by brand names such as Vicodin) and oxycodone (OxyContin) can be highly addictive.