Groton - The sirens wailed for just three minutes, but the echoes lasted much longer.

"My day started right about 7:30 (a.m.) when I was walking out of my house and I got a call from one of my dispatchers who just said, 'The Millstone sirens are going off and we're getting inundated with calls,' then hung up," said Groton's director of emergency management, Joe Sastre. "So yeah, it started with a bang."

On the morning of Oct. 7, emergency sirens, meant to alert residents of a disaster at the Millstone Nuclear Power Station in Waterford, activated. Though it was not a real disaster, the event gave town officials, who this week released a report on the response to the emergency, a chance to look at what worked and what didn't.

With so many calls coming into the town's dispatch center, it was difficult for emergency officials to even place outgoing calls to find out what was going on, Sastre said. Even after the sirens sounded, phones - both the 911 system and the non-emergency line - were jammed with residents calling to find out what was happening.

Because the alarms sounded before the start of business, Groton officials were unable to immediately reach staff at the nuclear power station.

"Early on in the process, I was fairly sure that there really wasn't a problem," Sastre said. "Once my dispatchers were able to get a break from the incoming 911 calls we called some of the other towns in the Millstone area and we learned it must have been an accidental glitch or activation."

Ultimately, Millstone officials said the alarms activated because of a glitch in the siren's recently upgraded computer programming, designed to silently check every morning at 7:30 a.m. that the devices were functioning properly. On the morning of Oct. 7, the automatic check activated the alarms on the sirens in town.

The sirens did not sound in the other area towns that are within 10 miles of the power station. In the event of a real emergency, the three-minute alarm would sound four times with one-minute breaks.

After the chaos ended, the sirens forced town officials to examine their response. Though the sirens were not alerting residents of a real emergency, the incident tested the town's response to a potential disaster.

"The unanticipated drills are a lot more worthwhile than the ones you plan for six months, when everybody shows up all ready to go," Sastre said. "Whether it's an accident or not, it behooves everyone to look at the situation as a learning experience: what did you do well, what didn't you do well, what do you need to do to handle things better next time."

A few weeks after the siren activations, Sastre wrote a memo about the town's response to the incident, detailing what worked and what didn't.

The town established new ways to communicate with the staff at Millstone regardless of the time and set up a contact list to rapidly send out information to the region's news media. Sastre's team quickly posted information to the town's public-access television channel and is looking at ways to post information to the town's Web site, which saw spikes in traffic the morning the sirens sounded.

"Like most municipal Web sites, it's all pretty static," Sastre said. "So we've sat down with the IT folks and we're going to come up with a way that we can update the site 24/7/365 whenever stuff happens, even if the IT guys aren't in yet."