OLD SAYBROOK, Conn. (AP) — The message broadcast over the local public address system from speakers all across town was startling: A terrorist attack was underway and people should seek shelter.The recorded message was somehow sent out by mistake Sunday afternoon, and now Old Saybrook officials are investigating how a dispatcher triggered the alert through what police called a series of errors.Shortly after the warning went out, the town sent Reverse 911 calls to residents telling them there was no terrorist attack and apologizing for the error.The dispatcher’s name wasn’t released, and it wasn’t clear how the alert was activated. A message seeking comment was left for a police department spokesman Monday.Fire Chief John Dunn posted a message on the Fire Department’s Facebook page Sunday saying town officials were taking steps to prevent a similar mistake from happening again.“We also apologize that the public experienced this issue today,” Dunn wrote. “We hope that today’s activation error won’t hamper the public’s future reaction to real emergencies.”Resident David Olsen said he heard some kind of message going out over the public address system Sunday but couldn’t make out any of the words. The alert was broadcast again about 30 seconds later, he said.“It’s concerning that there was somebody making that sort of mistake,” Olsen told WVIT-TV.First Selectman Carl Fortuna Jr. said he didn’t hear the alert, but the police chief told him about it shortly after it was issued. He said he doesn’t yet know what caused the error.“It was a mistake, and I assume measures will be taken so that mistake does not happen again,” Fortuna said.