Two girls play on cots at Humacao Arena refugee center while waiting for the imminent impact of Maria, a Category 5 hurricane that threatens to hit the eastern region of the island with sustained winds of 175 miles per hour, in Humacao, Puerto Rico, Tuesday, September 19, 2017. About 137 citizens arrived at the refuge from different parts of the eastern region of the Island.

SAN JUAN, Puerto Rico (AP) — One of the strongest hurricanes to ever hit Puerto Rico pummeled the island Wednesday, tearing off roofs and sending doors flying from hinges as officials warned Hurricane Maria would decimate the power company’s crumbling infrastructure and force the government to rebuild dozens of communities.

Maria, which has killed at least nine in the Caribbean, made landfall early Wednesday in the southeast coastal town of Yabucoa as a Category 4 storm with winds of 155 mph winds, and it was expected to punish the island with life-threatening winds for 12 to 24 hours, forecasters said.

People calling local radio stations reported that doors were flying off hinges and a water tank flew away in the island’s southern region. Meanwhile, widespread flooding was reported in the capital of San Juan, with water running down one apartment’s interior staircase.

“This is going to be an extremely violent phenomenon,” Gov. Ricardo Rossello said. “We have not experienced an event of this magnitude in our modern history.”

Metal roofs were already flying and windows were breaking as the storm approached before dawn, with nearly 900,000 people without power and one tree falling on an ambulance. Those who sought shelter at a coliseum in San Juan were moved to the building’s second and third floors, reported radio station WKAQ 580 AM. The storm was moving across Puerto Rico on Wednesday morning at 10 mph, with a gust of 113 mph reported in the capital of San Juan, according to the U.S. National Hurricane Center in Miami.

Maria, which had previously been a Category 5 storm with 175 mph winds, hit Puerto Rico as the third strongest storm to make landfall in the United States based on a key measurement that meteorologists use: air pressure. The lower the central pressure a storm the stronger it is and Maria’s pressure was 917 millibars, lower than Irma’s U.S. landfall of 929 millibars in the Florida Keys earlier this month.

Puerto Rico had long been spared from a direct hit by hurricanes that tend to veer north or south of the island. The last Category 4 hurricane landfall in Puerto Rico occurred in 1932, and the strongest storm to ever hit the island was San Felipe in 1928 with winds of 160 mph.

As Maria approached, U.S. President Donald Trump offered his support via Twitter: “Puerto Rico being hit hard by new monster Hurricane. Be careful, our hearts are with you- will be there to help!”

More than 4,400 people were in shelters by late Tuesday, along with 105 pets, Rossello said.

The storm’s center passed near or over St. Croix overnight Tuesday, prompting U.S. Virgin Islands Gov. Kenneth Mapp to insist that people remain alert. St. Croix was largely spared the widespread damage caused by Hurricane Irma on the chain’s St. Thomas and St. John islands just two weeks ago. But this time, the island would experience five hours of hurricane force winds, Mapp said.

“For folks in their homes, I really recommend that you not be in any kind of sleepwear,” he said during a brief news conference. “Make sure you have your shoes on. Make sure you have a jacket around. Something for your head in case your roof should breach. … I don’t really recommend you be sleeping from 11 o’clock to 4 (a.m.). … Be aware of what’s going on around you.”

Maria killed two people in the French Caribbean island of Guadeloupe and two people aboard a boat were reported missing off La Desirade island, just east of Guadeloupe, officials said.

About 40 percent of the island — 80,000 homes — were without power and flooding was reported in several communities.

The storm also blew over the tiny eastern Caribbean island of Dominica late Monday, where Prime Minister Roosevelt Skerrit sent out a series of dramatic posts on his Facebook page, including that his own roof had blown away.

“The winds are merciless! We shall survive by the grace of God,” Skerrit wrote before communications went down.

Hartley Henry, an adviser to Skerrit, said there have been seven confirmed deaths in the Caribbean country from Hurricane Maria. Hartley Henry didn’t give details about how the deaths occurred.

The storm knocked out communications for the entire island, leaving anyone outside Dominica struggling to determine the extent of damage, though it was clearly widespread. “The situation is really grave,” Consul General Barbara Dailey said in a telephone interview from New York.

She said she lost contact with the island about 4 a.m. At that point, officials had learned that 70 percent of homes had lost their roofs, including her own.

Flooding was a big concern, given the island’s steep mountains, cut through with rivers that rage even after a heavy rain. Dominica was still recovering from Tropical Storm Erika, which killed 30 people and destroyed more than 370 homes in August 2015.

Forecasters said the storm surge from Maria could raise water levels by 6 to 9 feet near the storm’s center. The storm was predicted to bring 10 to 15 inches of rain across the islands, with more in isolated areas.

To the north, Hurricane Jose weakened to a tropical storm Tuesday night. Forecasters said dangerous surf and rip currents were likely to continue along the U.S. East Coast but said the storm was unlikely to make landfall. Big waves caused by Jose swept five people off a coastal jetty in Rhode Island and they were hospitalized after being rescued.

A tropical storm warning was posted for coastal areas in Rhode Island and Massachusetts, and tropical storm watches were up for parts of New York’s Long Island and Connecticut.

Associated Press writers Ben Fox in Miami and Seth Borenstein in Washington contributed to this report.

David Cruz Marrero watches the waves at Punta Santiago pier hours before the imminent impact of Maria, a Category 5 hurricane that threatens to hit the eastern region of the island with sustained winds of 165 miles per hour, in Humacao, Puerto Rico, Tuesday, September 19, 2017. A woman and a child rest on cots while waiting at Humacao Arena refugee center for the imminent impact of Maria, a Category 5 hurricane that threatens to hit the eastern region of the island with sustained winds of 175 miles per hour, in Humacao, Puerto Rico, Tuesday, September 19, 2017. About 137 citizens arrived at the refuge from different parts of the eastern region of the Island.Citizens rest while waiting at Humacao Arena refugee center for the imminent impact of Maria, a Category 5 hurricane that threatens to hit the eastern region of the island with sustained winds of 175 miles per hour, in Humacao, Puerto Rico, Tuesday, September 19, 2017. About 137 citizens arrived at the refuge from different parts of the eastern region of the Island.Team leader Joey Rivera gives a speech while feelings of frustration surround the members of the rescue team from the municipality of Humacao, desperate to go out to attend several calls for help from citizens in need of assistance during the impact of Maria, a Category 5 hurricane that started to hit the eastern region of the island, in Humacao, Puerto Rico, Tuesday, Sept. 20, 2017. Puerto Rico faced Wednesday what officials said could be the strongest hurricane to ever hit the U.S. territory as they warned it would decimate the power company’s crumbling infrastructure and force the government to rebuild dozens of communities.