Barry rolled into the Louisiana coast Saturday, flooding highways, forcing people to scramble to rooftops and dumping heavy rain that could test the levees and pumps that were bolstered after Hurricane Katrina devastated New Orleans in 2005.

After briefly becoming a Category 1 hurricane, the system quickly weakened to the tropical storm as it made landfall near Intracoastal City, Louisiana, about 160 miles west of New Orleans, with its winds falling to 70 mph, the National Hurricane Center said. But officials warned that it could still cause disastrous flooding across a wide stretch of the Gulf Coast.

"This is just the beginning," Louisiana Gov. John Bel Edwards said. "It's going to be a long several days for our state."

The Coast Guard rescued more than a dozen people from the remote Isle de Jean Charles, south of New Orleans, where water rose so high that some residents clung to rooftops.

None of the main levees on the Mississippi River failed or were breached, Edwards said. But video showed water overtopping a levee in Plaquemines Parish south of New Orleans, where fingers of land extend deep into the Gulf of Mexico.

Nearly all businesses in Morgan City, about 85 miles west of New Orleans, were shuttered with the exception of Meche's Donuts Shop. Owner Todd Hoffpauir did a brisk business despite the pounding winds and pulsating rain.

While making doughnuts, Hoffpauir said he heard an explosion and a ripping sound and later went outside and saw that part of the roof at an adjacent apartment complex had come off.

In some places, residents continued to build defenses. At the edge of the town of Jean Lafitte just outside New Orleans, volunteers helped several town employees sandbag a 600-foot stretch of the two-lane state highway through town. The street was already lined with one-ton sandbags, and 30-pound bags were being used to strengthen them.

"I'm here for my family, trying to save their stuff," volunteer Vinnie Tortorich said. "My cousin's house is already under."