Joan Kennedy (search), the former wife of Massachusetts Sen. Edward M. Kennedy (search), is in the hospital recuperating from a concussion and a broken shoulder after a passer-by found her lying in a street, according to her son.

Kennedy, 68, was taken to Tufts New England Medical Center about 3 a.m. Tuesday, said Rep. Patrick Kennedy (search), D-R.I.

"We're indebted to some anonymous pedestrian who found her and picked her up and got her help," Patrick Kennedy told the Boston Herald for its Wednesday editions.

Details of exactly what happened and how she ended up in the street were unclear. There was no police report on the incident. Joan Kennedy, who divides her time between Cape Cod and a Boston condominium, has struggled with alcoholism.