NEW ORLEANS – The Gulf Coast braced Sunday for a potentially devastating hit from twin hurricanes as two dangerous storms swirled toward the U.S from the Gulf of Mexico and the Caribbean. Officials feared a history-making onslaught of life-threatening winds and flooding along the coast, stretching from Texas to Alabama.

A storm dubbed Marco grew into a hurricane Sunday as it churned up the Gulf of Mexico toward Louisiana. But, Marco’s intensity was fluctuating, forecasters said, and the system was downgraded to a tropical storm Sunday night.

Another potential hurricane, Tropical Storm Laura, lashed the Dominican Republic and Haiti, and was tracking toward the same region of the U.S. coast, carrying the risk of growing into a far more powerful storm.

Experts said computer models show Laura could make landfall with winds exceeding 110 mph (177 kph), and rain bands from both storms could bring a combined total of 2 feet (0.6 meters) of rain to parts of Louisiana and several feet of potentially deadly storm surge.