SEATTLE - Drive down the highway and you'll see 18-wheelers everywhere. What thieves see is an enormous opportunity for a big payday.

They got Ernesto Diaz as he delivered a shipment of women's clothing.

Two men choked and kicked him after he caught them swiping freight from his truck.

They made off with up to $65,000 worth of clothes.

"I was sick, and at the same time angry. I could do nothing," he said.

Thieves hit Bulldog Express Trucking in SeaTac. They drove the company's big rig, loaded with toys, right off the lot.

Owner Richard Douglas wondered if his company could survive the brazen heist.

"A $100,000-worth of product. I'm a little company, 25 employees, I can't take that kind of hit," he said.

Cargo theft is a nearly $50 billion criminal industry that strikes many port cities. Unless it includes a wild police chase, it's rarely headline news.

In spite of its thriving ports, the Northwest has remained remarkably immune from large-scale cargo theft, perhaps until now.

Video from a warehouse just outside of Issaquah shows how a wave of truck and trailer heists in the Puget Sound area have transpired. A stolen tractor truck smashes through the warehouse fence. It hooks up to a trailer loaded with clothes and takes off. 

Police agencies record the heists as just another vehicle theft, making it difficult to measure the size of the problem.

So the KING 5 Investigators zeroed in on the City of Kent, where warehouses and truck and trailer lots abound.

"In years past we'd hear about a trailer being stolen once or twice a year perhaps," said Paul Petersen of the Kent Police Dept. 

Kent police say within the past year, though, they've had a rash of truck thefts, but they can't say exactly how many.

By examining Kent crime reports, the KING 5 Investigators discovered dozens of thefts of big rig tractors, trailers, or both.

They included:

- A stolen semi full of REI clothing - a $250,000 load.

- Two trailers full of whirlpool washing machines.

- And a trailer full of motorcycles - a $200,000 payday for the thieves.

We found 37 reported truck thefts in Kent alone in a two-year period.

"Estimates of how much cargo crime hurts consumers are hard to come by, but it's clear you pay for it with every purchase,' said Ernesto Diaz.

One electronics industry group estimated that cargo theft costs consumers up to $150 more on each computer purchase.

While customers pay, the criminals often don't.

There was a new GPS tracking device in Richard Douglas' stolen truck. A little detective work led him to a Federal Way warehouse.

"To see a million dollars worth of stolen merchandise - it's pretty wild," he said.

His toys, and a $1 million load of stolen Victoria's Secret clothes, were stacked inside.

But Douglas learned about the priority of such crimes when he reported his find to the Federal Way Police Department.

"They said the truck was stolen in SeaTac, you've got to go there. I said 'Wait a second, I just saw hundreds of thousands of dollars in stolen freight in Federal Way and you can't do anything about it?'  He said 'Nope," said Douglas.

Thanks, in part, to Douglas' legwork, King County Sheriff's investigators and federal agents did arrest and charge a suspect in a rare Northwest prosecution for "interstate theft of goods."

More common are unsolved cases like that of Ernesto Diaz, who now carries a little protection, and a lot of awareness that thieves could strike again.