Eleven people, including five who were taken to hospitals, were hurt after a wooden walkway leading to Doubling Point Lighthouse in Arrowsic collapsed Saturday during the annual Maine Open Lighthouse Day.

The walkway collapsed suddenly just before 1 p.m. Saturday as people congregated on it while waiting to visit the lighthouse on the Kennebec River, south of Bath.

There was no sound or other warning before the walkway collapsed and people fell to the tidal area below, said Karen McLean, a member of the Friends of Doubling Point Light. The walkway to the lighthouse is 130 feet long, and the lighthouse is 23 feet above mean high water, according to the group’s website. The walkway had been checked recently for deterioration by volunteers, McLean said.

One person injured in the collapse was taken to Maine Medical Center in Portland, while four others were transported to Mid Coast Hospital in Brunswick, said Capt. Ashley Moody of the Bath Fire and Rescue Department. Six others were evaluated at the scene and did not require treatment, Moody said.

Moody said she could not disclose the type or severity of the injuries suffered.

Members of the Sagadahoc County Sheriff’s Office, Bath Police Department, and the Arrowsic Fire Department also responded to the accident and helped clear people from the scene, Moody said.

The lighthouse, built in 1899, is still an active Coast Guard aid to navigation but is owned and managed by the nonprofit Friends of Doubling Point Light, according to the American Lighthouse Foundation. People can visit the lighthouse and view it from the outside daily, but visitors are only able to go inside during the annual Maine Open Lighthouse Day, which this year was Saturday.

More than a dozen historic Maine lighthouses were expected to be open Saturday. The event often attracts more than 15,000 visitors.