Early in the afternoon of Aug. 29, as Hurricane Katrina bore down on the Gulf Coast, the phones inside the Louisiana State Police emergency operations center here began ringing with frantic pleas for help -- 467 that first day.

Families perched on rooftops, a grandmother trapped in an attic, gunfire outside a hospital. As the floodwaters rose, so, too, did the calls -- to 1,875 the following day, to 3,108 on Aug. 31, and to 3,284 on Sept. 1. The vast majority came from 70 miles away in New Orleans, but what was strange was not the volume of calls or that they were made, but how they ended up so far away from the people who needed help.

Floodwaters had forced 120 operators at the 911 center to abandon the New Orleans police headquarters. Emergency calls were supposed to be routed to the fire department but its main station was already abandoned. And so -- after hours of confusion -- many calls were shunted north to Baton Rouge, where unsuspecting emergency personnel suddenly found their phones ringing off the hooks.

The disintegration of New Orleans's 911 system carries national implications for future disasters, said public safety experts. While some communities boast sophisticated, high-tech centers with elaborate contingency plans, most cities have older systems lacking adequate backup measures for massive disasters.

"People in our country have gotten to believe that no matter what kind of trouble you get into, all you have to do is dial 911," said William Smith, chief technology officer at BellSouth, which is the phone carrier for New Orleans 911 calls. "That's not necessarily the case."

When airplanes struck the World Trade Center towers on Sept. 11, 2001, New York City lost its main emergency call router, but Rick Jones of the National Emergency Number Association said it was one of the few places in the country with a backup system to automatically reroute calls.

The 911 network is actually little more than a patchwork, subject to the budgetary pressures and technological whims of local and state governments, with no national standards.

Last year, Congress passed the Enhance 911 Act, which set aside $1.2 billion over five years to upgrade emergency systems and create a national coordinating agency for 911. But as Katrina was approaching, the money had still not been appropriated.

By the early hours of Aug. 30 at police headquarters, water was rising in the elevator shafts, approaching the second-floor communications equipment. Police Capt. Stephen Gordon began the evacuation of 120 operators. "It was like getting on the ark," he said later.

They were evacuated by boat to the city convention center. Gordon determined it was impossible to set up a makeshift call center there and ended up spending the next two nights sleeping on a hotel ballroom floor.

All the while, Gordon said, he believed the telephone company was transferring emergency calls to the state police.

While Gordon was trying to keep his crew safe, 82 BellSouth employees worked in chaos downtown. Although they had generators, food and water, police reported a National Guard unit had come under attack and their safety could not be guaranteed, Smith said. The day after the hurricane, under state police escort, the BellSouth workers fled to Baton Rouge.

In the meantime, BellSouth began rerouting 911 calls to an administrative line inside the flooded police building on South Broad Street that Gordon had abandoned days earlier. "We couldn't find anybody to ask them where to send the calls to," said company spokesman Jeff Batcher.

New Orleans officials remember it differently. Police Maj. James Treadway recounted a conference call with BellSouth officials late on Aug. 29, in which the company said some central offices were failing. "We asked them why other jurisdictions were getting our 911 calls and they didn't really have an explanation," Treadway said.

As the situation became more dire in New Orleans, state police in Baton Rouge were suddenly fielding calls they weren't equipped to handle, scribbling the information on sheets of paper.

"We called in extra employees and set up a phone bank, for lack of a better term, to answer and log these calls," said their supervisor, Sgt. Doug Cain. "We certainly weren't going to let these calls fall on deaf ears."

Within a day or two, Cain developed a secure Internet site that could be accessed by dispatchers in New Orleans. Each morning, the dispatchers took the most urgent calls and sent them to rescuers on boats in the city.

"It wasn't a Cadillac system," said Capt. Mark Willow, commander of the New Orleans police homeland security division. "But this filled a tremendous gap for us and saved a lot of lives."

In all, the makeshift Baton Rouge operation took 22,000 calls, ranging from the harrowing to relatives checking on the whereabouts of loved ones. But only a fraction could be handled at the time.

More than a month after the hurricane, a team of U.S. marshals laboriously worked through a backlog of the calls. Often, addresses -- even street names -- were gone, so the marshals used skills developed hunting fugitives, such as riffling through letters in a mailbox. Often the search failed to provide answer, but they found bodies.

Clues and unsolved mysteries remained, though. "You'd find a baby blanket wrapped around a bush," said Deputy Marshal Ross Hebert as he poked through debris in the city's mud-caked Lower Ninth Ward, "and you'd just pray whoever was in this was okay."

A month after Hurricane Katrina, U.S. Marshals Ross Hebert, left, and Mark Frederick worked to follow up on calls made to the emergency number. With a group on loan from the D.C. Fugitive Task Force, they often had to use their detective skills to account for incomplete information in New Orleans.