Four children and a woman were killed and at least seven injured after a four-storey building collapsed in northwest Delhi's Ashok Vihar Wednesday, police said. The injured have been rushed to Deep Chand Bandhu Hospital where a woman's condition is stated to be critical. The ground floor of the building housed a shop, which was closed while the first floor was vacant. A family lived on the second floor of the building. Two of the children, who were killed in the incident were brothers, aged around 10 years, and lived on the second floor. Two families were living on the third floor. The second family living on that floor lost its children -- a boy and his sister aged below five. The fourth floor was inhabited by a couple -- Narottam and Nisha. Nisha is critical, the police said. Some people are still feared trapped under the debris and rescue teams are working at the spot, the police said. -- PTI