PSA CRJ2 at Chattanooga on Jul 17th 2014, three doors indicated open on initial climb

A PSA Airlines Canadair CRJ-200 on behalf of US Airways, registration N246PS performing flight JIA-4637/US-4637 from Chattanooga,TN to Charlotte,NC (USA) , was climbing out of Chattanooga's runway 02 when the crew requested and was cleared to level off at 4000 feet and maintain runway heading. A few minutes later the crew reported that upon takeoff they got three doors indicated open and were running a checklist to figure out what the story was, but they would return to Chattanooga after the checklist. The crew subsequently advised they were pretty sure it was a false indication, they didn't believe the indications of three doors open. The aircraft returned to Chattanooga for a safe landing on runway 02 about 20 minutes after departure.