A four-storey residential building has collapsed in the Indian capital, killing at least seven people.. Residents said they feared some people may still be trapped in the rubble from the decades-old building that fell in Old Delhi. Rescuers using diggers to remove the debris freed a young boy trapped as he was passing by the building when it fell in the congested Chandni Mahal area. The area is known for its overcrowded buildings and loose wires criss-crossing narrow streets. Locals said they believed the building, built about eight decades ago from old construction materials, had been undergoing construction work that might have weakened the foundations. Police said seven people were killed and dozens injured, including four critically. Authorities were investigating, while critics accused the city of ignoring the state of Old Delhi\'s dilapidated buildings. Poor construction material and inadequate foundations are often blamed for collapses in India. A building collapsed in November, killing about 70 people in the capital, where prices for both land and rent are at premium levels thanks to a population quickly increasing with migrants seeking work.