SWAMPSCOTT-A fall down a flight of stairs at a construction site on Windsor Avenue led to a lockdown at Swampscott High School and a med flight to Boston.According to Swampscott Fire Department Spokesman Jennifer Bleiker, a workman on a new residential construction project at 44 Windsor Ave. fell down a flight of stairs at approximately 2:05 p.m.?He was conscious when the fire department arrived,” she said. “He is in his 40s and thought he had a possible back injury so he was med-flighted.”Swampscott Police Officer Candace Doyle said the victim was Fran Cullinan, who she said is employed by a company out of Lynn.Occupational Safety and Health Administration Spokesman John Chavez confirmed OSHA arrived at 44 Windsor Avenue late Wednesday afternoon. Chavez said the name of the company working at the site has not been confirmed and OSHA has a policy of not releasing the names of victims.The medical flight took off from Swampscott High School on Essex Street, which resulted in the high school being locked down briefly at dismissal time so the helicopter could land and take off.Superintendent Matthew Malone said the accident was not on school property, but the high school delayed dismissal for approximately seven minutes so the high school athletic field could be used for the medical flight.OSHA is still investigating the October scaffolding collapse at 41 Buena Vista St. that resulted in three workers being injured when a bracket supporting their scaffolding broke through a wall.At the time of that incident, Police Chief Ronald Madigan said improperly attached scaffolding appeared to be the cause of the accident. According to Madigan, A.F. Construction, which is based in Swampscott, was working as a sub-contractor to A.C. Castle Roofing, which is located in Peabody.According to a spokesman for A.C. Castle Roofing, the framers, who are not affiliated with his company, installed the brackets used to place the scaffolding on.On Wednesday, Chavez said that investigation is still ongoing and OSHA has up to six months to complete an investigation.