Students from New Orleans worried for friends and family yesterday as Hurricane Katrina rolled toward their hometown with wind speeds up to 175 mph that could bring a 28-foot storm surge, according to news reports. A storm surge is the rise in sea level that occurs during a large storm.

The mayor of New Orleans evacuated the below-sea-level city yesterday in anticipation of the Category 5 hurricane hitting early this morning.

Arturo Febry, New Orleans junior, was concerned for the safety of his family. His mother and grandmother evacuated the city yesterday, he said. His father, a doctor, stayed behind to care for injured residents.

G.M. Andrews/The Associated Press

Dale Munday of Dauphin Island, Ala., walks along the beaches of the island with his son Logan, left, and daughter Lauren, both 9, and their dog Rascal as the waters of the Gulf churn behind them Sunday, Aug. 28, 2005. Hurricane Katrina's effects were already being felt along the Gulf Coast as residents braced for the storm's expected Monday landfall near New Orleans.

“It’s hard because I can’t be home with them,” Febry said. “It’s always scary when you hear about these hurricanes, especially because any hurricane 2 or above, if it hits the Mississippi, can flood the city.”

DeMarco Smith, New Orleans sophomore, said his relatives boarded up their houses and drove to Houston, while some of his friends joined the thousands of people trying to get inside the Louisiana Superdome for shelter.

The 70,000-seat Superdome, home of the New Orleans Saints, is one of 10 emergency shelters the city has designated for residents who don’t have the means to leave the city.

“They seemed pretty calm,” Smith said. “It’s just another hurricane, but this one’s a little more damaging. They were just in a hurry to get there.”

The National Weather Service upgraded Hurricane Katrina to Category 5 yesterday as it crossed the Gulf of Mexico, meaning its wind speeds exceeded 155 mph and it could produce storm surges higher than 18 feet. Only three documented Category 5 hurricanes have touched land in the United States, the latest being Hurricane Andrew in 1992.

The National Hurricane Center called the hurricane “potentially catastrophic” and issued a hurricane warning at 1 p.m. yesterday for New Orleans and the rest of the Gulf Coast, meaning the hurricane was expected reach land within 24 hours.

The Associated Press

Nathaniel Brunsell, assistant professor of geography, said New Orleans was an especially vulnerable city because it sits an average of six feet below sea level.

“If we’re talking 12 feet, 15 feet of water coming in, it could potentially flood the entire city,” Brunsell said.