If drug interdiction can be compared to a giant game of whack-a-mole, federal law enforcement officials delivered one mighty wallop this week when they raided a container ship at Philadelphia’s port and discovered a staggering amount of cocaine.

Hidden inside seven shipping containers were 33,000 pounds (15,000 kilograms) of the illicit drug, one of the largest caches ever intercepted on U.S. shores and a quantity that’s almost “beyond comprehension,” as Patrick Trainor, a spokesman for the U.S. Drug Enforcement Agency in Philadelphia, put it Wednesday. Federal officials estimated the seized drugs had a street value of more than $1 billion.

The feds’ find was another sign that traffickers are turning to East Coast seaports as a result of increased law enforcement pressure along the country’s southwest border, a development cited by the drug enforcement agency in its latest national threat assessment. It was at least the third major bust in Philadelphia and New York since February.

“As soon as interdiction puts pressure on one place, it just pops up somewhere else. We’ve continually seen that,” said Nicholas Magliocca, a University of Alabama researcher who studies how traffickers adapt to interdiction. “As long as the demand is there, and there’s money to be made, traffickers are going to find a way.”

Cocaine use and overdose deaths are on the rise in the U.S. after years of decline as production has surged to record levels in Colombia, the source of about 90% of the U.S. supply.

Agents were doing another sweep Wednesday through thousands of containers on MSC Gayane, a cargo ship owned by Swiss firm MSC Mediterranean Shipping Co., but had not found any cocaine since their initial search on Monday, according to Stephen Sapp of U.S. Customs and Border Protection in Philadelphia.

Two members of the crew have been charged with conspiracy to possess cocaine aboard a ship, but details of their case are sealed.

An affidavit obtained by The Associated Press said that MSC Gayane was at sea off the west coast of South America when it was approached by more than a dozen boats loaded with cocaine. Crew members aboard the larger ship helped transfer the drugs, authorities said.

The cargo ship docked in Colombia, Peru, Panama and the Bahamas before arriving in Philadelphia early Monday. Federal authorities raided the ship later that day. The ship’s second mate was arrested after agents swabbed his hands and arms and detected traces of cocaine, an affidavit said.

“The 500 kilos that we got in March, good hit, good hit,” said Trainor, the Philadelphia DEA agent. “But was that a huge loss to the cartels? Probably not. But 15,000? Oh yeah. I’m sure somebody had a really, really bad day yesterday somewhere in South America.”

(AP)