BUXTON — The National Park Service closed the Cape Hatteras Lighthouse to the public after a section of a stairway broke off.

Park rangers found several weak spots in the lighthouse's original cast iron staircase during a safety inspection Tuesday. The discovery came after a one-pound piece of iron fell from the spiral staircase Monday afternoon, prompting the emergency inspection. No one was injured in the incident.

"We had a visitor that was actually almost struck with one of these pieces," says Ranger Warren Wrenn. "She was descending the stairs and a portion of one of the braces from the stairs above her head -- about 10 feet above her head -- fell and almost hit her."

The lighthouse was closed immediately after the support broke loose. A structural engineer from the park service is expected to complete an inspection of the lighthouse by the end of the week.

Park service officials say the lighthouse will be closed until further notice. Officials say they believe that the latest move of the lighthouse did not have anything to do with the incident.

Over 200,000 visitors climb the stairways of the 130-year-old lighthouse each year.