6.4 quake strikes Puerto Rico amid heavy seismic activity

A 6.4-magnitude earthquake struck Puerto Rico before dawn on Tuesday, the largest in a series of quakes that have struck the U.S. territory in recent days and caused heavy damage in some areas.

Puerto Rico's power authority said on Twitter that one of the country's main power plants, which sits near the epicenter, had been damaged, but officials expect to restore power to the island later Tuesday.

The U.S. Geological Survey said the quake hit at 4:24 a.m. just south of the island at a shallow depth of 10 kilometers. It initially gave the magnitude as 6.6 but later adjusted it. It said the quake was followed by a string of aftershocks from 5.6 to 4.5 in magnitude.

A tsunami alert was initially issued for Puerto Rico and the U.S. Virgin Islands, but later canceled.

Albert Rodrguez, who is from the southwest town of Gunica, said the tsunami sirens went off before officials canceled the alert. He said there is widespread damage in his neighborhood.

The road is cracked in the middle and it lifted up, he said.

The mayor of Guayanilla, Nelson Torres, told NotiUno radio station that the church in the public plaza of his town collapsed.

Vctor Hurfano, director of Puerto Rico's Seismic Network, told The Associated Press that it is hard to obtain reports of damage or injuries because communications are down for much of the island. He said officials in the large southern coastal city of Ponce told him there was widespread damage.

We expect that this will be the largest quake for now, he said. The aftershocks will continue for some time.

Puerto Rico's governor, Wanda Vasquez, told station Radioisla just before 6 a.m. that there had been no immediate reports of deaths.

She ordered government offices closed for the day and urged citizens to remain calm and not check damage to their homes until daylight.

A 5.8-magnitude quake that struck early Monday morning collapsed five homes in the southwest coastal town of Gunica and heavily damaged dozens of others.

It also caused small landslides and power outages. The quake was followed by a string of smaller temblors.

The shake collapsed a coastal rock formation that had formed a sort of rounded window, Punta Ventana, that was a popular tourist draw in the southwest town of Guayanilla.

Residents in the south of the island have been terrified to go into their homes for fear that another quake will bring buildings down.

The flurry of quakes in Puerto Rico's southern region began the night of Dec. 28. Hurfano told the AP that shallow quakes were occurring along three faults in Puerto Rico's southwest region: Lajas Valley, Montalva Point and the Guayanilla Canyon.

He said the quakes overall come as the North American plate and the Caribbean plate squeeze Puerto Rico.

One of the largest and most damaging earthquakes to hit Puerto Rico occurred in October 1918, when a magnitude 7.3 quake struck near the island's northwest coast, unleashing a tsunami and killing 116 people.