US school's nurse Sally Cox 'saw shooter's feet'

A school nurse at Sandy Hook school in Newtown, Connecticut, has recounted how she hid from the gunman who killed twenty children and six women on Friday.

Sally Cox told ABC News she heard a "loud popping noise" before taking cover underneath her desk, from where she could see the gunman's feet "20 feet away".

The gunman, who police say took his own life, has been identified by police as Adam Lanza, 20.