Seven persons were killed and at least 30 injured when a two-storeyed building housing a garment factory,BIG Garments,collapsed in Kalher village near Bhiwandi Thursday. The incident took place around 1.45 am at the 8,000-sq ft Arihant Complex,when over more than 50 workers were on night shift. The building was served a notice for illegal construction,despite which the work to add an additional third floor was on, said Santosh Patil,Upsarpanch of Kopar Gram Panchayat. He added that the notice to the owner of the godown,Hasmukh Dodiya,was served in March last year. S A Ahmed,Assistant Commandant,National Disaster Response Force (NDRF),said,The building was old and its pillars and base were not strong. The weight of adding a third floor,combined with heavy rain,led to the collapse. Gram Panchayat officebearers said the building was constructed in 2003. NDRF members received a distress call around 3 am and a team of 90 reached the site. The powerloom town of Bhiwandi is situated around 35 km north of Mumbai in Thane district. Rescue operations are under way. As many as 26 workers were pulled out of the rubble. Many workers are still unaccounted for. Some managed to escape before our team arrived. The exact number of people trapped is not known, said Ahmed. The injured were taken to Indira Gandhi Memorial Hospital. Four victims were later shifted to civic hospitals in Mumbai. The NDRF team is vertically scaling the building,removing layers of rubble. We are also using cameras to find survivors, said Ahmed. Four patients were transferred to Sion,Nair and J J Hospitals as their condition became critical, said Indira Gandhi Hospital medical superintendent Dr Nitin Mokashi. Of those admitted,20 patients took voluntary discharge and got admitted in other private hospitals,Mokashi added. Some have suffered serious injuries and are suffering from trauma, he said. The injured belong to Assam,Nepal,Bihar and Uttar Pradesh,hospital sources said.