COLON, PANAMA -- The stench rises from Balboa Street like an awful mirage, repelling pedestrians and settling in the heavy tropical air. The street is knee-deep in a fetid, week-old pool of dark water, half-covering mounds of garbage and emitting a stream of maggots.

"It disgusts me," said Edith Torres, a 40-year-old mother of two who lives in a tenement overlooking Balboa Street and its clogged sewer. "My baby is always sick and I know it's because of the the dirt and rotting garbage."

This is Colon, Panama's second-largest city and leading urban disaster. Situated on Panama's Atlantic coast about 40 miles northwest of Panama City, the capital, this compact city of 100,000 people, half of whom can't find a job and most of whom can't even hope for a better future.

In a country that for years has had a large, thriving middle class, Colon is the city that did not share in the wealth. It is the meanest, most dangerous place in Panama, and visitors to the country are routinely warned against going.

A few blocks down the street is the grand old Hotel Washington, a massive colonial structure fronted by luxurious tropical gardens. The Hotel Washington, once owned by the Hyatt hotel chain, has seen better days.

Water marks streak its facade like giant tears. The brass railings on the veranda are tarnished and twisted. On a recent Saturday night, only three guests were registered in the 82-room-hotel. There is just no reason to visit Colon.

Even by Central America's formidable standards of urban squalor, Colon is distinguished by its pervasive sense of decay, hopelessness and despair. For sheer filth and packed-in human misery, the city appears to have only one close rival -- the teeming slums of Port-au-Prince, the capital of the hemisphere's poorest nation, Haiti.

Colon's demise did not occur suddenly, nor was it the result of the former dictatorship of Gen. Manuel Antonio Noriega. But longtime residents say the decline was hastened by Noriega's rule and by the U.S. invasion last Dec. 20 that led to the dictator's ouster, and they describe conditions as never having been worse than they are today.

The city, once known as "the little cup of gold," has been in a continuous slide since its heyday during World War II, when nightclubs stayed open 24 hours a day to entertain American sailors and soldiers, and tourists from cruise ships strolled Front Street shopping for bargains.

The decline began after the war, with the completion of the Transisthmian Highway that connects Colon and Panama City, situated on the isthmus's opposite side on Panama's Pacific coast. Businesses, suddenly vulnerable to competition from the capital, closed up. Colon's young professionals, seeing opportunities vanish, moved to Panama City.

The Colon Free Zone, the world's largest duty-free zone after Hong Kong, generated some jobs and hefty profits. But little of the money made there was reinvested in Colon, and the slide continued. Under Noriega, the zone is said to have become more important as a source of kickbacks to the government than as a generator of jobs.

After the U.S. invasion, American troops and aircraft quickly took control of the Panamanian army base here, inflicting dozens of casualties on Panamanian troops and civilians. Then the U.S. forces withdrew to the city's outskirts. Chaos and looting followed, making a hash of the few businesses left in Colon's commercial center.

"Fortunately for some of us who live here and have a little money, there was something to loot, because otherwise we'd have been fighting for our lives," said a businessman.

Yet there is economic life in Colon. The city's port is still Panama's largest. The free zone, located in the middle of the city, is protected from Colon's gloom by high walls and barbed wire, like some prosperous prison.

But for a large majority of the city's residents, including those who have managed to obtain an education, the future is as murky as the standing water on Balboa Street.

Business owners have bought shotguns to protect themselves. The police, who carry pistols and shotguns, say they are badly outgunned by criminals, many of whom have AK-47 assault rifles. The city's main hospital is so poorly stocked that some patients bring their own sutures.

"There are no jobs," said Jacobo Salas, 63, a radio station owner who was born here. "So what's the use of studying or going to school? It doesn't pay to do anything because you can't find a job.

"Nobody cares, nobody gives a damn," he said. "There was a lot of happiness when the U.S. invaded, but don't think the pro-U.S. euphoria will last. When people realize that the millions of dollars aren't coming, that the poor aren't a priority and that people are going to continue going hungry . . . all of this is a detonator that will make this city explode. The target will be the Panamanian government, and then the United States."

Said Nicolas Delgado, a lawyer and Roman Catholic priest at Colon's main cathedral, "This place is in complete chaos. . . . Our 'liberators' were not conscious of their obligations, and now we're sitting on a time bomb."