Almost half of the cargo that enters the United States makes its way through the ports of Long Beach or Los Angeles.
As the nation's busiest seaport complex, it's a cornerstone of American commerce. But the place is also a potential target for terrorists, which is why so much has changed since the attacks of September 11th.
"Before 9/11, everybody had their own intel units, everybody had their own information, and sharing that information would be difficult," said Javier Larios, Customs and Border Protection section chief officer.
The U.S. Customs and Border Protection (CBP) agency was created in 2003 as part of the federal government's reaction to 9/11.
The CBP is in charge of guarding the nation's ports. It is one seven federal agencies under the Department of Homeland Security.
"Now that we're under one umbrella under Department of Homeland Security, CBP and the U.S. Coast Guard and all the other agencies, Immigration and Customs Enforcement, can come together, share common information and intel to be able to identify the terrorists and terrorist-related cargo," said Larios.
But the changes at the seaport since 9/11 go beyond shared information. The CBP has developed ways to target high-risk cargo by analyzing manifests electronically. It used to be that cargo ships only had to provide paper manifests to customs inspectors, and often that information was incomplete or inaccurate. But not anymore.
"That's really important for us because that helps us reduce the tremendous amount of cargo that comes through this port," said Larios.
A shipping container vessel arrives at the port every seven seconds. There's no way for inspectors to physically examine every single one, so they identify high-risk targets. It's like looking for a needle in a haystack, but they're working to make that haystack a lot smaller.
"We certainly cannot look at every single piece, but by screening every piece of information, can help us identify the high risk, and therefore concentrate our resources to the high risk for issues that are terrorist-related," said Larios.
If the cargo comes from a new importer or from a high-risk country, or if anything seems out of the ordinary, the container is X-rayed using a mobile scanner.
If something looks irregular, officers sometimes inspect the contents on the docks.
Other times they send suspicious cargo to bonded warehouses, where officers are looking for everything from dangerous chemicals and pharmaceuticals to replicas of high-dollar items like purses or shoes.
"We become closer to the importer so now we know who you are, what you import, where the merchandise is coming from, so when we see an anomaly in your shipments, we're going to take a look at that," said Guillermina Escobar, chief officer, Customs and Border Protection.
Before any shipping container makes its way out of the seaport, it will go through one of 90 radiation detectors, all of which were installed in the years following 9/11.
"They are so sensitive at detecting radiation that they can detect a 1-inch nail in a fortified container loaded with cargo," said Larios.