SHEFFIELD, Vt. -- State police probing the disappearance of a 78-year-old grandmother are appealing for help from anyone who took photographs or video at a Labor Day event her son says she attended in her tiny town.

Pat O'Hagan worked as a volunteer at the Sept. 6 event in Sheffield, a town so small it has no stores and no stoplights, her son Shawn O'Hagan said Sunday. Police are following up on all avenues in their investigation, he said.

Pat O'Hagan, a widow and grandmother of nine, was reported missing from her home Sept. 11, just days after the Sheffield event, when a friend arrived to pick her up for a rug-hooking meeting and she wasn't there.

Police believe she was abducted from her home. Authorities say she's mentally alert and there's no reason to believe she wandered off.

Detectives continued following up leads over the weekend. Area all-terrain vehicle clubs and volunteer fire departments pitched in.

On Sunday, state police asked to hear from anyone who recorded images at the annual Sheffield Field Day event. But the police would have no further comment on their interest in the event, spokeswoman Sgt. Tara Thomas said.

FBI agents have joined the search for O'Hagan, with police combing corn fields, barns, abandoned buildings and a quarry in the dairy farming community, to no avail.

O'Hagan, who's originally from Chelmsford, Mass., moved with her husband to northern Vermont about 15 years ago, and they renovated a deteriorating white clapboard house before he died in 2001, her son Terry O'Hagan said. She lives alone and likes camping and kayaking, her family says.