Hurricane Maria's destructive tear across the Caribbean is well underway, with the storm obliterating parts of Dominica and threatening "catastrophic" damage to Puerto Rico.
"No generation has seen a hurricane like this since San Felipe II in 1928," Puerto Rico Gov. Ricardo Rosselló said Tuesday. "This is an unprecedented atmospheric system."
He urged Puerto Ricans to find safe shelters immediately, as emergency workers "will not be available to help you once the winds reach 50 mph."
"We need to keep in mind that we must also protect the lives of these first responders. It's time to act and look for a safe place if you live in flood-prone areas or in wooden or vulnerable structures," Rosselló said.
Maria has already has pounded Dominica with 160 mph (257 kph) winds and caused "widespread devastation," Prime Minister Roosevelt Skerrit said Tuesday.
The Category 5 hurricane shredded the prime minister's house overnight and left much of the island -- population 73,000 -- in ruins.
"So far we have lost all what money can buy and replace," Skerrit posted on Facebook Tuesday. He said his greatest fear was "news of serious physical injury and possible deaths as a result of likely landslides triggered by persistent rains."
A few hours earlier, the Prime Minister posted, "My roof is gone. I am at the complete mercy of the hurricane. House is flooding."
Maria is now the strongest hurricane on record to make landfall in Dominica, a former French and British colony whose economy relies heavily on tourism and agriculture.
Now, Maria is taking aim on Puerto Rico and Islands already crippled by Hurricane Irma.
'Don't go out under any circumstances'
As of midday Tuesday, Maria was centered about 150 miles (240 kilometers) southeast of St. Croix and was headed west-northwest at 10 mph.
While Maria moves closer to St. Croix, the Virgin Islands and Puerto Rico, preparations against life-threatening storm surge, flooding and destructive winds "should be rushed to completion,' the National Hurricane Center said.
Puerto Rico said its biggest airport, the Luis Muñoz Marín International Airport near San Juan, will close at 7 p.m. ET Tuesday. Airports in Ponce and Aguadilla will close today at 6 p.m.
A hurricane warning is in effect Tuesday for Guadeloupe, Dominica, St. Kitts, Nevis, Montserrat, the US and British Virgin Islands, Puerto Rico, Culebra, and Vieques.
"A dangerous storm surge accompanied by large and destructive waves will raise water levels by as much as 7 to 11 feet above normal tide levels in the hurricane warning area near where the center of Maria moves across the Leeward Islands and the British Virgin Islands," the hurricane center said.
Guadeloupe's regional government tweeted a stern warning to residents Tuesday: "Don't go out under any circumstances."
Puerto Rico says Maria 'will be catastrophic'
Maria will pummel the Virgin Islands and Puerto Rico on Tuesday night and Wednesday as "an extremely dangerous Category 4 or 5 hurricane," the National Hurricane Center said.
That would make Maria the first Category 4 or 5 hurricane to make landfall in Puerto Rico in 85 years.
In the capital city of San Juan, residents cleared store shelves of water and other supplies.
Gov. Rosselló has declared a state of emergency. And US President Donald Trump issued an emergency declaration for Puerto Rico to aid with federal assistance.
Puerto Rico sheltered many of the evacuees who fled from other Caribbean Islands during Hurricane Irma earlier this month. Now those evacuees and native Puerto Ricans are bracing for devastation.
"This is an event that will be damaging to the infrastructure, that will be catastrophic," Rosselló said. "Our only focus right now should be to make sure we save lives."
The governor said 500 shelters are available on the island.
"We expect to feel storm winds, tropical storm winds, (from) Tuesday up until late on Thursday. That's about two-and-a-half days of tropical storm winds," Rosselló said.
"On Wednesday we will feel the brunt -- all of the island will feel the brunt of sustained Category 4 or 5 winds."
The Puerto Rico Convention Center in the capital San Juan to the north -- which is still housing Hurricane Irma evacuees from other Caribbean islands -- is preparing to accept thousands of residents as the worst of the storm is felt.
Martinique largely spared
One bit of good news emerged from the Caribbean: The French island of Martinique suffered no major damage, the French Interior Ministry tweeted Tuesday.
Maria knocked out power to about 50,000 homes, and 10,000 homes had no water. But overall, the damage assessment was "reassuring," the French Interior Ministry said.
The director general of French civil security, Jacques Witkowski, said only two people on Martinique suffered minor injuries.
In just 30 hours, Maria's intensity exploded from 65 mph on Sunday to 160 mph by Monday night, the National Hurricane Center said.
The British Foreign Office said more than 1,300 troops are on standby, either on affected islands or in nearby locations, ready to help after Maria tears through.
One military team has been deployed to the British Virgin Islands, and a British military reconnaissance team is on standby to go to the British territory of Montserrat.
The HMS Ocean is set to arrive in the area at week's end with 60 tons of government supplies.
Another hurricane, Jose, is also churning in the Atlantic and has spawned tropical storm warnings for part of the US East Coast.
While forecasters don't anticipate Jose making landfall in the US, it's still expected to cause "dangerous surf and rip currents" along the East Coast in the next few days, the hurricane center said.