Tropical Storm Ernesto has left nearly half of Puerto Rico without power and caused severe flooding across the island, with reports indicating over 700,000 customers affected. The storm, which has now strengthened to a Category 1 hurricane, brought torrential rains exceeding 10 inches in some areas, exacerbating the already fragile power grid. Puerto Rico's Governor, Pedro Pierluisi, announced that President Biden approved a disaster declaration to provide federal assistance, as emergency officials prepare for potential landslides and further flooding. Public schools have been closed and shelters opened as officials warn residents to stay indoors. The storm has also affected the U.S. Virgin Islands, where 46,000 customers lost power, and flash flood warnings are in effect. LUMA Energy, the power utility, is mobilizing crews to address outages, but the island's electrical system remains vulnerable due to insufficient modernization.