A vandalized backup generator is seen at a Movistar facility in Los Teques, Venezuela, November 21, 2016. REUTERS/Marco Bello

CARACAS, Dec 15 (Reuters) — The clanging sound of collapsing metal shook awake the residents of Guayabal, an industrial zone in the outskirts of Venezuela's capital, last October.

Then they watched a 40-meter (131 feet) telecoms tower tumble after thieves had stripped even the screws holding up the installation, which was owned by state telecoms provider CANTV and rented out to private operator Movistar.

The theft, which also included copper cables and a generator, was the latest of six at that station this year and one of hundreds worsening crime-rife Venezuela's already shaky telecoms.

Amid a brutal economic crisis that has brought galloping inflation and forced many Venezuelans to skip meals due to food shortages, scarce industrial materials can fetch a tall price.

"Everything can be sold now and people are doing anything to survive," said Victor Martinez, manager of Movistar Venezuela, the local unit of Spain's Telefonica, speaking next to another station whose batteries and compressors were stolen.

"We'd like to invest in modernizing the network, not in protecting these stations as if they were war bunkers," Martinez said while surrounded by equipment rubble that will cost 4 billion bolivars to replace, or about $5.9 million at the weakest official rate under Venezuela's currency controls.

A fallen antenna is seen at a vandalized Movistar facility in Guarenas, Venezuela, November 23, 2016. REUTERS/Marco Bello

Crime has worsened service quality in a sector already reeling from chronic underinvestment due to the currency controls that stymie imports of spare parts and new technologies.

It also affects internet speed, which the United Nations says is the slowest in Latin America.

Thefts have left some areas, including the coastal city of Coro, totally off the communications grid, residents say.

Movistar, Venezuela's second biggest telecoms company, suffered 636 thefts this year, up 179 percent from 2015, with losses ranging from big electricity generators and batteries to copper cables and screws that are resold on the black market.

An anti-government protester walks next to a burning kiosk during a protest at Altamira square in Caracas, Venezuela. Reuters/Jorge Silva

Venezuelan-owned Digitel says four of its stations are robbed daily, up from under two per week last year. CANTV, which dominates the market, did not respond to a request for information, but has in the past called on users to denounce vandalism.

The leftist government of Nicolas Maduro has also set up a phone line, 0-800-atennas, so people can report theft.

Companies now are mostly trying to modify networks to reduce dependency on theft-prone stations.

"Beyond that, there's not much we can do without the help of state security groups," said Jose Luis Fernandez, commercial director of Digitel. "We expect a worsening of service quality in the short-term."

(By Diego Oré; writing by Alexandra Ulmer; editing by Bill Trott)