Kolkata: Four persons were injured when a concrete chunk from a roof of a building inside Calcutta Medical College and Hospital (CMCH) fell offon Friday. The incident took place at the Regional Institute of Ophthalmology department of the hospital in the morning. According to hospital sources, the concrete chunk fell on the relatives of the patient, who were waiting outside the operation theater in the eye department. The incident occurred when an operation was going on inside the operation theater. After being informed the security personnel of the hospital rushed to the spot and brought the situation under control. The hospital authorities claimed that the incident had no impact on the operation. Also Read – Rain batters Kolkata, cripples normal lifeAccording to the hospital, the patients’ relatives were not seriously injured. Some of the victims had, however, received head injuries. They were immediately taken by the hospital staff and attended by doctors. The incident triggered tension among patients visiting the eye department of the hospital and their family members. The patients’ relatives were immediately removed from the place and the entire area was cordoned off to avoid any further incident. It was learnt from hospital sources that renovation works were carried out by the Public Works of Department in the Ophthalmology department recently. The hospital authorities are probing into the incident and figuring how it took place despite the repair works. All the injured victims are stated to be stable. A probe has been initiated.