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 on 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 Corp.'s storage depot that spewed a column of black smoke into the sky near the capital San Juan on 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.

President Barack Obama declared an emergency in Puerto Rico, mobilizing federal disaster relief resources for the area affected by the fire, the White House said.

The fire has destroyed 18 of the storage facility's 40 tanks. The governor said only five tanks were still fully ablaze on 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 on 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 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 on 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 fight the fire. Foam used in putting out oil fires was shipped 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.

"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, while a spokeswoman said its operations had complied with all local and federal regulations.

(Editing by Jane Sutton)