SAN JUAN — A failing dam prompted emergency evacuations of two towns in northwestern Puerto Rico on Friday as the US territory struggled with flooding, an island-wide blackout, and other dangers in Hurricane Maria’s wake.
The National Weather Service in San Juan said the municipalities of Isabela and Quebradillas, home to some 70,000 people, were being evacuated with buses because of a crack in the Guajataca Dam.
The 345-yard dam, which holds back a man-made lake covering about 2 square miles, was built decades ago.
The operators of the dam reported that the failure was causing flash-flooding downstream, the weather service said. The government called the situation ‘‘extremely dangerous.’’
Communications to outlying areas of the island have been hampered by the storm.
‘‘It’s a structural failure. I don’t have any more details,’’ Governor Ricardo Rossello said from the capital, San Juan. ‘‘We’re trying to evacuate as many people as possible’’
Meanwhile, all across the battered island, anxious residents feared power could be out for weeks — or even months — and wondered how they would cope.
Some of the island’s 3.4 million people planned to head to the United States to temporarily escape the desolation. At least in the short term, though, the soggy misery will continue: Additional rain — up to 6 inches — is expected through Saturday.
In San Juan, Neida Febus wandered around her neighborhood with bowls of cooked rice, ground meat, and avocado, offering food to the hungry. The damage was so extensive, the 64-year-old retiree said, that she didn’t think the power would be turned back on until Christmas.
‘‘This storm crushed us from one end of the island to the other,’’ she said.
The death toll in Puerto Rico stood at six but was likely to rise.
At least 27 lives in all have been lost around the Caribbean, including at least 15 on hard-hit Dominica. Haiti reported three deaths; Guadeloupe, two; and the Dominican Republic, one.
By Friday afternoon, Maria was passing northeast of the Turks and Caicos with winds of 125 miles per hour. A hurricane warning remained in effect for those islands as well as the southeastern Bahamas. The storm is not expected to pose a threat to the US mainland.
Israel Molina, 68, found that Maria had ripped away roofing from his Israel Mini Market in San Juan.
‘‘I’m from here. I believe we have to step up to the task. If everyone leaves, what are we going to do? With all the pros and the cons, I will stay here,’’ he said, and then paused. ‘‘I might have a different response tomorrow.’’
In Puerto Rico, the electric grid was in sorry shape long before Maria struck. The territory’s $73 billion debt crisis has left agencies like the state power company broke. It abandoned most basic maintenance in recent years, leaving the island subject to regular blackouts.
Diana Jaquez, one of the owners of the Coquette hair salon in the Santurce area, assessed damage from the storm with her husband Friday as their children played nearby. She said she hadn’t decided whether to leave the island.
‘‘Business has dropped a lot,’’ she said. ‘‘People have other priorities than looking good.’’
Outside her store, more than 100 people stood in line waiting to get money out of an ATM machine and hoping there would still be some cash left when their turn came.
At the Pentagon, Major General Derek P. Rydholm, deputy to the chief of the Air Force Reserve, said it is still impossible to say how long it will be before communication and power are restored.
He said mobile communications systems are being flown in but acknowledged ‘‘it’s going to take a while’’ before people in Puerto Rico will be able to communicate with their families outside the island.