Fire rages at Puerto Rico fuel depot

(CNN) -- Officials say it could take a week to extinguish a massive fire that burned Friday afternoon at a fuel storage complex in Puerto Rico, sending a thick black cloud of smoke over large parts of metro San Juan.

iReporter Maria Marquez photographed the flames early Friday from the 17th floor of her San Juan condominium.

Eleven fuel tanks at the Caribbean Petroleum Corp. facility in the city of Bayamon, near San Juan, were ablaze, Gov. Luis Fortuno said. Firefighters were trying to cool the remaining 29 to keep them from igniting, he said.

"I don't think there's ever been a fire like this in Puerto Rico," Fire Lt. Jose Atorre told CNN affiliate WLII-TV.

Fortuno said he declared a state of emergency for the area so Puerto Rico can get aid from the Federal Emergency Management Agency.

The storage and refinery complex sits on San Juan's bay, and Fortuno said officials are working to protect it from being affected.

"We have serious worries that the bay or other bodies of water could be contaminated," he said.

The company's Web site says the complex has storage facilities for gasoline and gasoline-related products.

Newspaper and TV reports said a 4-inch pipe from a lagoon on the property was broken, preventing firefighters from using 2 million gallons of water from the lake to battle the blaze. About 150 area firefighters and 215 National Guard personnel were battling to keep the blaze from spreading.

One person suffered smoke inhalation and was taken to a hospital, Fortuno said. At least 350 people were evacuated to a nearby stadium. iReport.com: See, share, send images of the explosion

The smoke can be toxic for people with breathing conditions, and officials have asked nearby residents to stay away, the governor said. The wind shifted to the north Friday morning, blowing most of the smoke over less-populated areas and the Atlantic Ocean.

Officials were investigating the cause of the blaze, which started shortly after midnight. Puerto Rico is a U.S. protectorate, which means federal officials are involved.

FBI Agent Shawn Deturn confirmed that authorities were looking into graffiti found on at least one San Juan tunnel that mentioned the fire. The spray-painted message at the Minillas Tunnel in San Juan said "Boom, fire, RIP, Gulf, Soul, ACNF." A second tunnel was reported to have the same message. Officials do not know who or what ACNF is, Deturn said.

Caribbean Petroleum owns the Gulf Oil brand in Puerto Rico.

Fortuno said Friday that all leads must be followed.

"There could be many reasons [for the fire]," he said. "We're not going to guess. But there has to be an investigation."

Caribbean Petroleum, which owns 200 gas stations in Puerto Rico and several inland distribution facilities, supplies much of the island's fuel. But Department of Consumer Affairs Secretary Luis Rivera Marin said there is enough fuel on hand for 24 days, and 16 million gallons of gasoline were in transit to the island. He also froze prices at the level they were at 8:06 a.m.

Officials transferred 295 inmates from a high-security prison in the area to other facilities, which they declined to identify for security purposes. Another 1,600 prisoners were moved from another nearby facility. An additional 200 prison officials were brought in to handle the transfers, Fortuno said.

Video on WLII showed a caravan of white vans with sirens blaring transferring the prisoners.

San Juan police said they activated all units: explosives, transit, tactical operations and SWAT.

The National Guard Combat Support Team was monitoring air quality, and local environmental officials were working with the U.S. Environmental Protection Agency to install monitors near the blaze.

Schools in Bayamon, San Juan, Toa Baja and Catano were closed.

Puerto Rico Road 28 was closed, and Roads 5 and 22 were partially closed.

Flights into and out of Luis Munoz Marin International Airport in San Juan were not affected, an airport official said.

Some residents said they woke to an extremely unusual sight.

"I didn't expect to see a mushroom cloud from my house," said Justin Gehrke, a U.S. Army civilian employee who filed an iReport for CNN.

CNN's Jackie Castillo contributed to this report.