The Ghaziabad Development Authority (GDA) has ordered an independent probe into the building collapse in Shalimar Garden. GDA Vice Chairman Narendra Chaudhary said, the action would be taken against those engineers and other staff who were found violating building laws. He said, the inquiry report will be out within a week. The under-construction four-storey building had collapsed on Saturday evening, killing four persons and injuring 14 others, all construction workers and their kin. A contractor and two supervisors have been arrested and a manhunt has been launched for the builders of the structure. A magisterial probe was ordered into the incident on Sunday. Town Planning Department of the GDA claimed that, the plot measuring 860 square feet was allowed for the construction of six flats only at two floors, but the builder constructed 48 flats at four floors in an unauthorised manner. The police has registered a criminal case against seven persons.