The governor of Puerto Rico, Wanda Vázquez, declared a state of emergency throughout Puerto Rico and activated the National Guard.

“In 102 years, Puerto Rico had not experienced anything like this,” she said.

The 6.4-magnitude quake, which struck 5 miles southwest of Tallaboa on Puerto Rico’s southwestern coast, was recorded at 4:24 a.m. local time, according to the U.S. Geological Survey. It was the second consecutive day that an earthquake hit the island before dawn, terrifying residents scared about the cumulative effect on older buildings.

The governor warned that the seismic activity is expected to continue in the coming days, as most of the island struggles with the huge power outage. A power plant in the south sustained significant damage, she said. The outage also left nearly a third of the island without running water.

The governor warned people whose houses do not meet building codes to seek shelter. About 255 people were already staying in shelters Tuesday.

“There is nothing to indicate from the experts who know these types of disasters that this is going to be bigger than what we have seen so far, but yes we will have repetitions and tremors that we will be feeling,” Vázquez said. “This is going to be happening for the next few days. How long? We cannot predict.”

White House officials said President Donald Trump had been briefed on the earthquakes and that the Federal Emergency Management Agency director, Pete Gaynor, had been in touch with senior Puerto Rican officials.

Nelson Martínez Guillén, 73, died in the city of Ponce after a wall fell on him, Mayor Mayita Meléndez said. A woman suffered a broken leg after she was pinned under a wall.

“The people are scared,” Meléndez said. “There are homes that are totally destroyed.”

Tremors were felt through the region, and people living near the beaches are desperate to get out of their homes for fear of tsunamis, she said.

“It’s not safe,” Meléndez said. “The earth is moving constantly.”

A 60-year-old city employee begged for help from the mainland.

Reynaldo González, whose uncle, Martínez, was killed, said that his uncle’s apartment, in the Jardines del Caribe neighborhood, was undergoing construction work, and the bathroom wall next to Martínez’s bed collapsed on him as he was apparently getting up, Gónzalez told WAPA radio.

“We heard a roar” at the time of the quake, González said, but it was not until later, when his father called out to Martínez, that they realized what had happened.

Stephy Valentín, 22, of Ponce, said she and her family rushed to hide under the kitchen table after they were awakened by the strong shaking. All they could do was pray, she said. “It was scary. We’ve never experienced something like this, and it’s still going on. Aftershock after aftershock.”

Angel Vázquez Torres, director of emergency management in Ponce, said nine people were injured in the city during the earthquake, including a woman who was trapped in her home for three hours after a wall collapsed on her, pinning her leg.

“This has been very difficult,” he said. “No one can prepare for a disaster like this.”

Torres said he had slept less than four hours in the last two days.

There is no electricity in the city, and some parts of Ponce are without water, he said. “There are tremors happening at this very moment.”

The widespread power outages included San Juan, the capital. The Puerto Rico Electric Power Authority said all of its power plants had gone offline after its “auto protection” systems had been activated. The utility said it hoped to restore electricity elsewhere later Tuesday.

But mindful of the enduring electrical problems that plagued the island after Hurricane Maria in 2017 — full power was not restored until nearly a year later — New York Gov. Andrew Cuomo said he was dispatching technical experts from the New York Power Authority to aid in the response.

The U.S. National Tsunami Warning Center said there was no related tsunami threat. Local authorities initially issued a tsunami watch before canceling it, according to Puerto Rico’s emergency management agency.

The quake’s magnitude was initially reported as 6.6 and later downgraded. Three strong aftershocks with preliminary estimates of 5.6, 5.2 and 4.5 magnitude followed the big quake. A bigger aftershock, of 5.8 magnitude, hit at 7:18 a.m. local time.

Vázquez excused nonessential public employees from work for the day. Mayor Nelson Torres Yordán of Guayanilla said on the radio that there was a lot of fear on the streets. “There’s hysteria,” he told a local television station.

The Immaculate Conception church in the center of town partly collapsed. The church withstood a huge quake in 1918 with some damage, the Rev. Melvin Díaz Aponte said. This time, both bell towers crumbled. The nave stands, but it is fragile.

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The last Mass held Monday took place outside in the courtyard because Monday’s quake made people nervous to be inside. On Tuesday, the courtyard was full of debris.

“For those who have lived here their whole lives, this is their history,” Díaz said. “Their sacraments, their wedding.”

A 4.8-magnitude aftershock interrupted him. Then a member of the congregation came up to say hello.

“We will rebuild,” he reassured the woman.

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Puerto Ricans ran out of their homes before dawn after being shaken awake by the quake. Officials urged people to stay calm and remain at home, but many people still got into their cars and drove to higher ground, prompting unusually heavy traffic in some areas in the dark. Many homes and buildings in southern coastal towns partially crumbled or sustained serious damage.

Hospital patients, some of them in wheelchairs, were evacuated to a parking lot in the city of Ponce. Patients at Hospital Damas were going back into the building when the biggest aftershock hit, forcing them to evacuate again, the NotiCentro television station reported.

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Around Puerto Rico, police officials begged for help.

“Please pray a lot,” said Adeli Quiñones, an agent with the police command center in Aibonito. “We’re supposed to be providing security for people, but we’re also scared for our own families.”

Quiñones said much of the island is without light and people are trying to buy tickets out of Puerto Rico, or heading inland, away from threatened buildings.

“We’re all just waiting for the next one,” she said.

Angel Ramos, a police officer in Mayagüez, said no one had been injured in the city and buildings appeared to be intact. Still, residents were flooding supermarkets trying to stock up on water and food.

“They’re getting ready,” he said.

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On Monday, a 5.8-magnitude quake and aftershocks terrified residents, leveled homes and destroyed a well-known natural rock formation. Smaller tremors have been occurring since the night of Dec. 28, all clustered in the same offshore area.

Puerto Rico’s representative in Congress, Jenniffer González, noted that the preparations from the earlier quake this week saved lives — classes were canceled at schools, some of which went on to experience serious damage.

In the town of Guánica, the main roof of a middle school collapsed after Tuesday morning’s quake, said Harold Rosario, a spokesman for the town’s mayor.

“The school is uninhabitable,” he said. “It’s done.”

He said people who had been forced to flee their homes were taking refuge in a sports arena. Many of them, he said, were weeping with exhaustion and fear. “They’re too afraid to go back to their homes,” he said.

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Glenda Colón, 44, from the town of Juncos, went to town with her family to get supplies and wound up on the street. She said the sound of shaking storm doors on local businesses was frightening.

“I was with the baby and the little dog, and we felt the car move from side to side,” Colón said.

“Everything’s good,” Colón added. “Nervous.”

Dariane Torres, 29, who lives in Penuelas, said the earth moved like gelatin.

“The tremors were too strong,” she said. “They were so strong that they gave me panic attacks.”

Marcos Pagán, 31, of Lajas, watched the quake from the seashore, where he operates a water taxi.

“It felt horrible,” he said. “I thought it was the end of the world.”

This article originally appeared in The New York Times .