Hurricane Ernesto re-strengthened on Sunday, posing significant risks for life-threatening surf and rip currents along much of the U.S. East Coast. Initially downgraded to a tropical storm on Saturday night, Ernesto’s sustained winds surged back to 75 mph, just surpassing the threshold for a Category 1 hurricane, according to the National Hurricane Center (NHC).

The hurricane, located approximately 520 miles south of Halifax, Canada, was moving north-northeast at an increased speed of 17 mph. The NHC warned that Ernesto is expected to intensify further on Sunday before weakening again into a tropical storm by Tuesday as it nears southeastern Newfoundland.

In response to the dangerous rip currents, New York City officials closed beaches in Brooklyn and Queens to swimming on Sunday. Similarly, New Jersey authorities cautioned beachgoers to stay out of the water unless lifeguards were present, particularly in Atlantic City, where the combination of high seas and high tide could lead to coastal flooding.

Tragically, two men drowned in rip currents off Hilton Head, South Carolina, on Friday, though it remains unclear if Ernesto was directly responsible, as rip currents are a year-round hazard in the area. The victims, identified as Ralph Jamieson, 65, and Leonard Schenz, 73, died in separate incidents.

Additionally, a stilted home in Rodanthe, North Carolina, was dramatically swept into the ocean by incoming waves, though no injuries were reported. The National Park Service urged visitors to avoid the beaches near the collapse site.

With NOAA buoys recording wave heights of 5 to 6 feet along the coast from North Carolina to Rhode Island, the NHC advised that dangerous surf and rip currents could persist from Bermuda to Canada in the coming days. Coastal flood advisories were issued for 10 million people on Sunday, signaling imminent or ongoing moderate to major flooding.