Hurricane Fiona grew more powerful Tuesday as it rolled past Puerto Rico and the Dominican Republic after pounding the islands with up to 30 inches of rain, triggering overwhelming flooding, mudslides and destruction.

The storm reached the Turks and Caicos Islands as a Category 3 hurricane, blasting the British territory of about 40,000 people with maximum sustained winds of 115 mph. The government imposed a curfew and urged people to flee flood-prone areas as the archipelago braced for a storm surge of 5 to 8 feet.

In the Dominican Republic, more than 1 million people were without running water and 700,000 homes and businesses were without power, the national Emergency Operations Center said.

►More rain was forecast through the week in parts of Puerto Rico, and conditions were not expected to significantly improve. "Catastrophic and life-threatening flash, urban, and moderate to major river flooding, as well as mudslides, are likely for southern and eastern Puerto Rico through Tuesday due the rainfall from Hurricane Fiona," the National Weather Service warned.

Fiona, which strengthened to a Category 3 storm overnight, is forecast to intensify over the next couple of days, the National Weather Service said: .

The head of FEMA said Tuesday the agency will be sending “hundreds of additional staff’’ to Puerto Rico in the coming days, besides the 1,000-plus already in the island responding to Hurricane Fiona – about 700 of whom had been aiding recovery efforts from Hurricane Maria, which struck with devastating force exactly five years ago.

More than 1,000 residents of the Dominican Republic were living in shelters Tuesday after Fiona tore through the country.

The National Weather Service warned of another 1 to 4 inches of rain for much of Puerto Rico into Wednesday morning.

Narciso Cruz put the flooding in perspective by comparing it to the massive amount of water Category 4 Hurricane Maria brought five years ago Tuesday.

Fiona made landfall as a Category 1 storm Sunday afternoon on the southwestern coast of Puerto Rico, then made landfall again early Monday on the Dominican Republic's east coast.

In hard-hit Salinas, a municipality of about 30,000 people on the southern coast of Puerto Rico, Mayor Karilyn Bonilla estimated 2,500 people had their homes swamped. The National Guard led a team of responders in more than 500 water rescues, and Bonilla expressed gratitude for lifesaving efforts "that put their own at risk." .

"Jill and I are keeping the people of Puerto Rico in our prayers as Hurricane Fiona passes over your beautiful island," Biden tweeted

Fiona struck Puerto Rico almost five years to the day after Hurricane Maria slammed the island on Sept

The destruction wrought across the island by Fiona included a temporary bridge in the city of Utuado that was built after Hurricane Maria