Hurricane

Authorities in the town of Vega Alta on the north coast said they had been unable to reach an entire neighborhood called Fatima, and were particularly worried about residents of a nursing home.

“I need to get there today,” Mayor Oscar Santiago told The Associated Press. “Not tomorrow, today.”

Federal officials said a dam upstream of the towns of Quebradillas and Isabela in northwest Puerto Rico was cracked but had not burst by Saturday afternoon. Video from a helicopter flight showed water pouring from the Guajataca dam. Federal officials said Friday that 70,000 people were being evacuated, but Javier Jimenez, mayor of the town of San Sebastian, said he believed the number was far smaller.

He said only several hundred families were told to leave the banks of the Guajataca River. San Sebastian is to the west of the dam and outside the worst flood zone.

The discrepancy could not immediately be explained.

The 345-yard (316-meter) dam, which was built around 1928, holds back a man-made lake covering about 2 square miles (5 square kilometers). More than 15 inches (nearly 40 centimeters) of rain from Maria fell on the surrounding mountains, swelling the reservoir.

An engineer inspecting the dam reported a “contained breach” that officials quickly realized was a crack that could be the first sign of total failure of the dam, U.S. National Weather Service meteorologist Anthony Reynes said.

“There’s no clue as to how long or how this can evolve. That is why the authorities are moving so fast because they also have the challenges of all the debris. It is a really, really dire situation,” Reynes said.

Officials said 1,360 of the island’s 1,600 cellphone towers were downed, and 85 percent of above-ground and underground phone and internet cables were knocked out. With roads blocked and phones dead, officials said, the situation may worsen.

“We haven’t seen the extent of the damage,” Rossello told reporters in the capital. Rossello couldn’t say when power might be restored.

Maj. Gen. Derek P. Rydholm, deputy to the chief of the Air Force Reserve, said mobile communications systems were 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.

The island’s 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.

Rosello said he was distributing 250 satellite phones from FEMA to mayors across the island to re-establish contact.

At least 28 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.