Customs officers stationed at the commercial border crossing in Nogales, AZ, made the largest fentanyl seizure ever recorded at any port of entry after a K-9 alerted others at the post that a haul of illegal narcotics was somewhere inside a vehicle at the checkpoint.

According to AZcentral.com, officers inspected the vehicle and discovered 254 pounds of fentanyl inside a hidden floor compartment of an 18-wheeler carrying cucumbers. According to the National Institute on Drug Abuse, synthetic opioids—primarily illegal fentanyl—are the most common drugs involved in overdose deaths in the United States.

The record-setting seizure on Saturday contained enough fentanyl to kill more than 115 million people—roughly equivalent to a third of the entire United States population.

In addition to the fentanyl, officers also seized 395 pounds of methamphetamine. Combined, the two drug busts have an estimated street value of $4.6 million.