BALTIMORE -- A Spirit Airlines flight traveling from Baltimore to Orlando had to return shortly after takeoff Friday night after the plane experienced a "suspected mechanical issue," the company said.Video submitted to WJZ appeared to show an engine fire.The plane took off from Baltimore/Washington International Thurgood Marshall Airport just after 8:20 p.m., looped back over Annapolis and landed again about 8:50 p.m., according to the flight tracking site Flight Aware. The plane, an Airbus A321, landed back at the airport "after the crew declared an emergency," the Federal Aviation Administration said."The plane landed safely at BWI, and Guests deplaned under normal procedures," Spirit Airlines said. "Safety is our top priority, and the plane will be removed from service and inspected by our maintenance department."Multiple people on the ground near the airport reported hearing loud booms as the plane flew overhead.