ROBSTOWN, Texas (ValleyCentral) — A traffic stop that occurred on the morning of Dec. 2 led to a discovery of fentanyl worth $1.8 million.

U.S. Border Patrol agents and the Nueces County Sheriff’s Office seized the largest recorded amount of liquid fentanyl seized in the United States, said RGV Border Patrol Sector Chief Gloria Chavez.

According to the chief’s tweet, 25 pounds of the drug were located in a compartment with the vehicle’s gas tank.

Chavez also said the amount is enough to kill a population of 5.6 million people, about 2 1/2 times the size of Houston.