SAN JUAN, Puerto Rico, Sept 18 (Reuters) – The entire island of Puerto Rico was without power on Sunday as Hurricane Fiona made landfall causing severe flooding and mudslides before heading towards the Dominican Republic, a government agency said. The center of the storm made landfall on the southwest coast of Puerto Rico near Punta Tocon at 3:20 p.m. ET (1920 GMT) with maximum sustained winds of about 85 miles per hour (140 kilometers per hour), clearing the threshold for a Category 1 hurricane, the National Hurricane Center said. The NHC said the storm caused “catastrophic flooding” through early Sunday morning. Sign up now for FREE unlimited access to Reuters.comSign up Power was cut across the island of 3.3 million people, LUMA Energy, the island’s grid operator and Puerto Rico’s electricity authority, said in a statement. LUMA said it could take several days to fully restore power. Puerto Rico’s ports are closed and flights from the main airport are canceled. Torrential rain and mudslides were also forecast for the Dominican Republic as the storm moves northwest, with the Turks and Caicos Islands likely to experience tropical storm conditions on Tuesday, the NHC said. “These rains will cause life-threatening and destructive flooding and urban flooding across Puerto Rico and the eastern Dominican Republic, along with mudslides and landslides in areas of higher ground,” the agency said. President Joe Biden approved a declaration of emergency for Puerto Rico on Sunday, a move that authorizes the Federal Emergency Management Agency to coordinate disaster relief and provide emergency protective measures. read more The rains have increased in intensity since Sunday morning, along with strong winds, residents said. Denise Rios, who lives in the southwestern city of Hormigueros, said she was left without power after a strong gust of wind and rain began around noon. “It hasn’t stopped since,” he said. “It’s raining hard and the wind is blowing hard. I’m calm, but alert.” A wide swath of Puerto Rico was forecast to see 12 to 16 inches (30 to 40 centimeters) of rain, while parts could get hit with up to 25 inches (63.5 centimeters), according to the NHC. Puerto Rico’s grid remains fragile after Hurricane Maria in September 2017 caused the largest blackout in US history. In that Category 5 storm, 1.5 million customers lost power with 80% of power lines down. Authorities have opened more than 100 shelters and closed beaches and casinos, and residents have been told to seek shelter. So far one death linked to Fiona has been reported on the French Caribbean island of Guadeloupe. Authorities said a man was found dead Saturday after his home was swept away by floodwaters there. France will recognize a state of natural disaster for Guadeloupe, President Emmanuel Macron said on Twitter on Sunday. read more Sign up now for FREE unlimited access to Reuters.comSign up Reporting by Ivelisse Rivera in San Juan. Additional reporting by Nathan Layne in Wilton, Connecticut and Tim Reid in Los Angeles. Editing by Grant McCool, Lisa Shumaker and Daniel Wallis Our Standards: The Thomson Reuters Trust Principles.