New Orleans and Baton Rouge phone lines were overwhelmed with calls, making it difficult for four College students from the same high school, Isidore Newman in Uptown New Orleans, to reconnect. Lester Leung '06, who spent the summer in Cambridge, set up a message board online.

Eric J. Suh '07, one of the four, was in Lake Charles, midway between New Orleans and Galveston. His family was planning to move in with relatives in Boston, the nearest family, and find a school for his younger brother.

"We've been watching the news closely to see if we could catch a view of our house or the neighborhood, but we've only gotten vague glimpses that don't say much, while all we've heard are rumors about which areas are dry and which areas are flooded," Suh wrote in an e-mail. "It's a bit up in the air right now."

In September 2004, when Hurricane Ivan threatened New Orleans but ultimately swerved past it, Hani N. Nakhoul '06 evacuated by booking an earlier flight to Boston for the start of classes. But Katrina was different. Nakhoul left home in Metairie, a New Orleans suburb south of Lake Pontchartrain, at dawn on Sunday morning.

"I actually had a feeling that it would kind of be going for the long haul, so I packed all my stuff, all my clothes that I wear on a regular basis, all my books and things to keep me occupied for a long time," said Nakhoul, who didn't know the status of his home. "I didn't expect what to happen to happen, I didn't expect all of New Orleans to be uninhabited, but I did expect it be real."

On Wednesday, he was staying with friends in Knoxville, Tenn. and planned to head to Montreal, where his parents hoped to find new jobs and his 16-year-old brother a new high school.

"We're not trying to linger on it," he said. "We're just trying to make plans as best we can as things come up. So we're just trying."

—Joshua P. Rogers contributed to the reporting of this article.

—Staff writer April H. N. Yee can be reached at aprilyee@fas.harvard.edu