A three-member panel has been set up by the Hyderabad authorities to probe whether a three-storied residential building, into which a Navy plane crashed during an air show, had an illegal extra floor. The Kiran MK-II plane, which was part of the 'Sagar Pawan' aerobatic team participating in a display at the 'India Aviation show 2010', crashed on Wednesday into the building at New Bowenpally, killing its two pilots and another man on the ground. Officials said, the top floor of the building into which the plane crashed not only had a penthouse but also a cell phone tower atop. On a query whether the building owner had obtained permission to construct extra floor and installation of tower, Secunderabad Cantonment Board CEO C Ravindra said, they have set up a committee and investigating if the building was constructed in an unauthorised manner. Building owner L Ramesh Kumar, a retired engineer who has sought compensation in view of damage to his building, said there were several buildings in the locality with ground plus two floors and also a penthouse. <br/> <br/>