Winds shift as fire burns Puerto Rican oil depot

SAN JUAN (Reuters) - Firefighters made progress in containing a raging fire at an oil storage depot in Puerto Rico, but shifting winds threatened to bring the toxic smoke closer to populated areas, officials warned Saturday.

However, authorities said air quality remained good, well below toxicity levels that would prompt more evacuations.

"Right now, there is not any reason to evacuate anyone else," the Caribbean island's Governor Luis Fortuno said.

An explosion triggered the blaze at the Caribbean Petroleum Corporation's storage depot that spewed a column of black smoke into the sky near the capital San Juan Friday. Authorities in the U.S. territory evacuated more than 1,000 residents on Friday from areas near the fire, and 530 people spent the night in shelters the government set up in public facilities.

The fire has destroyed 18 of the storage facility's 40 tanks. The governor said only five tanks were still fully ablaze Saturday, while four had collapsed in the flames and others appeared to have burned out but were still smoldering.

"The fire is contained. We don't expect it to spread from there," said Fire Chief Pedro Vazquez.

Firefighters focused on chilling the unaffected tanks and containing the flames. There were 130 firefighters battling the blaze with the support of 30 fire trucks and other equipment.

The National Weather Service issued a bulletin Saturday warning residents in six towns west of San Juan that winds were turning more easterly, which was pushing the toxic smoke plume their way. Rain was another concern, and the weather service urged residents in the towns to remain indoors.

The smoke, which loomed thousands of feet above the raging fire in a tight cone throughout Friday, was hovering much closer to the ground Saturday and was also more dispersed than previously.

The Environmental Quality Board monitoring the air in communities closest to the blaze -- Toa Baja, Catano and Bayamon -- had yet to show any significant worsening in air quality, so no more evacuations were foreseen.

The National Guard took over the lead coordinating role in managing the disaster Saturday, as additional heavy equipment from the National Guard and island pharmaceutical firms was brought in to battle the blaze.

Authorities erected a temporary pipeline from San Juan Bay to supply seawater to help fight the fire. Additional foam used in extinguishing oil fires was shipped in from the U.S. Virgin Islands.

Officials were concerned over contamination and dug a makeshift pool on the scene to collect the water used to extinguish the blaze, which was being trucked out to a treatment plant.

Sections of the De Diego Expressway and other roads remained closed and the Coast Guard kept up a security zone in a section of San Juan Bay near the blaze.

"Nobody is prepared for a fire like this. I'm calling on the 4 million Puerto Ricans to thank God tomorrow because this could have been much worse than it was," the governor said.

Company officials said they did not know what started the fire.

"The priority has been to extinguish the blaze and assure the least impact possible," Caribbean Petroleum Corporation spokeswoman Frances Ros said.

She said the company's operations had complied with all local and federal regulations.

"It would be irresponsible for management or anyone to say what happened here. Once the fire is extinguished, we will be able to really advance the investigation," Ros said.

(Editing by Jane Sutton)