Worried relatives have turned to the web in their desperate search for friends and relatives missing in the wake of Hurricane Katrina.
Evacuees are using the web to find out what's left of their homes
Several sites have sprung up to help people trace each other, and to glean information about whether their homes are flattened or flooded.
The internet has also become a focal point for relief efforts as people volunteer their services and donate to charities working in the devastated area.
Popular community advertising site Craigslist, where many in the US turn to find jobs, apartments and online love, has set up special pages on its New Orleans site to help people locate missing relatives and volunteer to help.
Messages pour in
One woman was looking for an 84-year-old relative who was recovering from surgery. Her relatives lost contact with her after the hospital she was in was evacuated.
It is just one of several sites where people are posting messages in the hopes of finding lost loved ones.
Thousands of messages poured into the online bulletin boards of Nola.com, the website of the New Orleans newspaper.
On one of the newspaper's weblogs, teacher Diana Boylston told of her wait for word of her students.
"From a hotel room in Houston, I sit tortured in from of the TV hoping to see a shot of their building or a face," she wrote. "What I want to know is will my students be alive."
People also tried to find out whether their homes and businesses were still standing or had been spared the destructive floods.
And even as there were calls for a complete evacuation of the city, people were trying to find ways back in. Authorities are urging people not to try to return.
The message boards also became a clearing house for other sites and services set up to help.
They pointed people to a database of missing persons set up on the site GulfCoastNews.com.
And some mentioned the neighbourhood message boards set up by blogger Kenneth Greenlee of N.O. Pundit.
He was evacuated to Galveston Texas before Katrina hit and was relieved by early reports that his home 10 blocks east of the historic French Quarter appeared to have escaped the flooding seen elsewhere.
On the Gulf Coast of the state of Mississippi, reporter Don Hammack of the Sun Herald tried to answer readers' questions about their homes and businesses on the Eyes on Katrina blog.
In the wake of the storm, he wrote: "I've gotten several hundred specific queries about friends, families and neighbourhoods."
He asked his readers for patience. "Please bear with us while we try to pick ourselves up off the mat."
The newspaper has now set up an "I'm OK" telephone line for relatives in the area.
Blog for relief
The internet is not only a hub for communication but also for action, as those wanting to help offer their money, services and even homes.
At Craigslist, people from across the United States were offering free housing to those made homeless by the killer hurricane.
Bloggers declared Thursday 1 September as Hurricane Katrina: Blog for Relief Day as they banded together in a relief effort to raise money for charities.
Set up by the blogger behind TruthLaidBear.com, hundreds of bloggers from 11 countries responded to the call to mark Thursday as Hurricane Katrina: Blog for Relief Day.