(CNN) -- A raging blaze at a fuel storage complex in Puerto Rico lit up the night sky Friday near San Juan as firefighters battled to keep it from spreading further.



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



Fifteen of the 40 tanks at the Caribbean Petroleum Corp. facility in the city of Bayamon were ablaze more than 19 hours after an explosion of unknown origin rocked the complex, Gov. Luis Fortuno said at an evening news conference. The governor had put the tally at 11 a few hours earlier.



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



The fire started shortly after midnight, when at least one fuel tank exploded. Residents described a surreal scene after the blast woke them from their sleep and shattered windows miles away.



"I was in bed and all of a sudden heard this really horrible sound, so I ran upstairs and thought the whole town had blown up," said Teo Freytes, who filed an iReport for CNN.



"The explosion blew out windows here in Old San Juan," he said. "It's still burning outrageously."



Others woke up Friday morning 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 also filed an iReport.



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 near San Juan's bay, and Fortuno said officials are working to protect the water from being affected.



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



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



"We have been monitoring the water visually and we have installed preventive pads and other material to contain a spill," said Pedro Nieves, chairman of the Puerto Rico Environmental Quality Board. "No oil has reached the water."



But Nieves said that Caribbean Petroleum has a history of spills and "there was potential that it had contaminated ground water." He said he did not have any specifics on hand and that his organization was more focused on containing the current problem of fire and smoke. The U.S. Environmental Protection Agency did not immediately return calls about the company's environmental history.



Newspaper and TV reports said a 4-inch pipe from a lagoon on the complex 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.



"This is a tremendous amount of smoke, and fire contains all kinds of irritants and this is oil that is burning," said Mary Mears, spokeswoman for the Environmental Protection Agency region that includes Puerto Rico. "It's smoke, so you're going to notice coughing, tearing, maybe a sore throat."



The wind shifted to the north Friday morning, blowing most of the smoke over less-populated areas and the Atlantic Ocean. The smoke plume also is rising 5,000 feet straight up before starting to drift, which keeps it away from people on the ground.



"The average air quality for Puerto Rico is still good," Nieves said.



But the wind was expected to change Saturday morning, blowing the smoke over a large part of the island west of the fire.



Officials also are concerned that rain mixed with the smoke could lead to acid rain. Authorities urged residents to bring in animals and their food and for people not to go out
How many people have been evacuated? Were there any evacuations near San Juan? Where is the fuel depot fire? What could be affected? Where was the massive fuel depot fire?
At least 350 350 people Puerto Rico the water Caribbean Petroleum Corp. facility in the city of Bayamon
question: How many people have been evacuated?, answer: At least 350 | question: Were there any evacuations near San Juan?, answer: 350 people | question: Where is the fuel depot fire?, answer: Puerto Rico | question: What could be affected?, answer: the water | question: Where was the massive fuel depot fire?, answer: Caribbean Petroleum Corp. facility in the city of Bayamon