In Colombia, residents have come face to face with the threat of having their daily lives disrupted by the increasing threat of terrorist attacks on the country's basic infrastructure. Colombia's largest left-wing guerrilla group has turned to attacks on the networks of essential services, such as water, electricity and heat, to terrorize the people.
A line of soldiers climbs down 600 steps into the bowels of a dam which holds back a huge mountain lake, Bogota's water supply. At the bottom of the tunnel, a tense spray of water shoots out from a heavy industrial valve, where a three inch-hole was recently blasted into it.
"The guerrillas put a bomb under the valve," said Eduardo Barcenas, chief engineer for the water company. "Fortunately, the damage was limited, but if they'd placed the dynamite differently, it might have taken out the whole valve - and the reservoir would have poured out... a disaster. It was the first time the rebels dared touch Bogota's most essential commodity - water."
Over the past six weeks, the country's largest guerrilla group, known as the FARC, has taken on a new tactic, instead of human targets, it is taking aim at infrastructure in the cities, as well as the countryside.
"More than 38 in the region," said Bogota mayor Antanas Mockus. "And we had some bombing on the gas system for the city."
At city hall, the mayor lists off the guerrilla attacks this past month, besides the bombing of the water dam, electricity towers and natural gas lines have been dynamited by the FARC.
The city has never been so vulnerable and the mayor admits, there's not much he can do to stop it. There are hundreds of electricity towers - most of them outside the city, in the mountains - easy prey.
"In this moment it would be hard to protect all the infrastructure," he said. "It would require a lot of soldiers and it would be costly. And when you look internationally you have only very very rich societies that can put systemically resources on protection. So we are vulnerable."
So far, the city's been able to reroute the electricity to avoid blackouts. But power and natural gas prices will go up next month in the capita - between 5 and 15 percent.
And forces of nature could make things much worse. If el Nino blows in again this year, sparking a very dry summer - Colombia's hydroelectric power production will plummet. Abraham Corman, head of a power distributors federation, says that could create an energy crisis.
"Basically because of both issues, having this electric transmission system falling apart and el Nino," he said. "Nobody can survive that."
This is exactly the kind of pressure the guerrillas want Bogota residents to feel. The FARC began these infrastructure attacks when they were still immersed in peace talks with the Colombian government. Daniel Garcia-Penya, a former government peace negotiator, believes the guerrillas adopted the strategy as a way of intimidating city residents and politicians into accepting their political and economic demands.
"They're trying first of all to get the effects of the war to be felt by the urban population," he said. "Close to 80 percent of Colombians live in the large cities that are relatively unaffected by the conflict. Nevertheless it also generates the boomerang affect. A great repudiation, a great anger."
Colombia's President Andres Pastrana broke off peace talks definitively last week and many observers believe the infrastructure attacks helped fuel the government's decision. And since the talks ended, the attacks have escalated.
The army is currently battling to regain control over a former demilitarized zone from the rebels who held it for three years during the peace talks. In response the guerrillas have dynamited electricity and telecommunications towers around the zone.
"In San Vicente de Caguan, the largest town in the zone, there's a total block on electricity and telephone communication," said mayor Nestor Leon Ramirez. "We may have to take emergency measures if this continues."
Five years back, the FARC rejected the use of infrastructure attacks on the ideological grounds that cutting water or power hurts the poor as much as the rich.
But now, they've clearly thrown ideology to the wind. It may be the September 11 terrorist attack in New York and Washington that showed the guerrillas the power of urban shock tactics. Financial analysts worry if the war on infrastructure continues, it may eventually undermine the stability of Colombia's economy.