Media playback is unsupported on your device Media caption Eyewitnesses said the building collapsed "like a pack of cards", as Rajini Vaidyanathan reports 
 
 At least 45 people have died, including 15 children, after a building being constructed illegally collapsed near the Indian city of Mumbai, police say. 
 
 About 70 people were injured and many are feared trapped beneath the seven-storey bloc in Thane after the incident on Thursday evening. 
 
 Building work was going on even though four floors were already occupied. A search for survivors is continuing. 
 
 Building collapses are common with poor construction practices often blamed. 
 
 Analysis The building collapse underlines the issue of illegal construction in India. Police say the builder of the high rise used sub-standard construction material and did not possess an occupation certificate. There are hundreds of similar illegal high-rises in the Mumbai region. Due to a high population growth, there is always demand for cheap housing. And homes in illegal buildings sell at a lower price compared to those in legal ones. Activists also allege that unscrupulous builders often pay hefty bribes to authorities who turn a blind eye to these illegal structures and do not take any action against the builders. 
 
 The authorities now say they are searching for the officials who were supervising the building works. 
 
 'Like a pack of cards' 
 
 The BBC's Sameer Hashmi, who is at the scene of the incident, says rescue workers are still trying to clear the debris. 
 
 Most people living in the building are from the low-to-middle income groups, our correspondent adds. 
 
 Witnesses say the construction of the building started just six weeks ago and in that time seven floors were built rapidly and the eighth floor was under construction. 
 
 Even though the construction was incomplete, the builders had allowed families to move in, our correspondent adds. 
 
 On Thursday evening a section of the building collapsed, bringing the entire structure down, police said. 
 
 Rescue efforts continued throughout the night and dozens have been injured. 
 
 It is not yet clear what caused the collapse, but police inspector Digamber Jangale told the BBC it appeared to be due to the use of substandard building material. 
 
 Police said a case had been registered and an inquiry had begun and that they were searching for the builders to arrest them. 
 
 One witness, named only as Ramlal, said the building appeared to tilt before quickly collapsing. 
 
 "The building collapsed like a pack of cards within three to four seconds," he said. 
 
 India's deadly collapses 19 Dec 2012: 13 die in Wagholi, Maharashtra 
 
 24 Sept 2012: 6 die in Pune, Maharashtra 
 
 15 April 2012: 23 workers killed in blanket factory collapse in Jalandhar 
 
 16 Nov 2010: 69 killed and more than 80 injured in Delhi 
 
 18 Aug 2010: School building collapse kills 18 children in Uttarakhand 
 
 26 Jan 2010: 23 killed in Bellary, Karnataka 
 
 23 Sept 2009: Chimney of a power plant in Chhattisgarh caves in, 40 killed 
 
 13 Aug 2008: 20 die in Mumbai 
 
 18 July 2007: 29 killed in Mumbai In pictures: Mumbai building collapse 
 
 Schoolgirl Hasina Shaikh, who had lived with her family on the fifth floor, said she was lucky to be still alive. 
 
 "I had just returned from school and was changing when the building started shaking and came down on us," she told Mumbai's DNA newspaper. 
 
 "When I regained consciousness later, I was in the hospital." 
 
 In other recent incidents 
 
 At least 13 people died when part of a half-constructed building collapsed in the Wagholi area of Maharashtra in December 
 
 At least six people were killed when a building collapsed in Pune city in Maharashtra in September ||||| A building being constructed illegally in a suburb of India's financial capital collapsed into a mound of steel and concrete, killing at least 41 people and injuring more than 50 others, authorities said Friday. 
 
 Rescue workers carry a stretcher near the site where a residential building collapsed in Thane, Mumbai, India, Thursday, April 4, 2013. At least 6 persons were killed and 40 were injured when an under... (Associated Press) 
 
 Rescue workers carry the body of a man near the site of a residential building which collapsed in Thane, Mumbai, India, Thursday, April 4, 2013. At least 6 persons were killed and 40 were injured when... (Associated Press) 
 
 Rescue workers carry the body of a women near the site of a residential building collapsed in Thane, Mumbai, India, Thursday, April 4, 2013. At least 6 persons were killed and 40 were injured when an... (Associated Press) 
 
 Rescue workers look for trapped people after a residential building collapsed in Thane, Mumbai, India, Thursday, April 4, 2013. At least 6 persons were killed and 40 were injured when an under-construction... (Associated Press) 
 
 Rescue workers look for trapped people after a residential building collapsed in Thane, Mumbai, India, Thursday, April 4, 2013. At least 6 persons were killed and 40 were injured when an under construction... (Associated Press) 
 
 Rescue workers look for trapped people after a residential building collapsed in Thane, Mumbai, India, Thursday, April 4, 2013. At least 6 persons were killed and 40 were injured when an under construction... (Associated Press) 
 
 The building in the Mumbai suburb of Thane caved in Thursday evening, police said. Rescue workers with sledgehammers, gasoline-powered saws and hydraulic jacks were struggling to break through the tower of rubble in their search for possible survivors. Six bulldozers were brought to the scene. 
 
 "There may be (a) possibility people have been trapped inside right now," local police commissioner K.P. Raghuvanshi said Friday. 
 
 More than 20 people remained missing and three floors of the building remained to be searched, said R.S. Rajesh, an official with the National Disaster Response Force who was at the scene. 
 
 `'All the three floors are sandwiched ... so it's is very difficult for us," he said, adding that rescuers were continuing to pull survivors from the wreckage. 
 
 The dead included at least 11 children, police said. 
 
 At least four floors of the planned eight-story building had been completed and were occupied. Workers had finished three more floors and were adding the eighth when it collapsed, police Inspector Digamber Jangale said. Some of the dead were construction workers staying in the building as they worked on it, Jangale said. 
 
 The building did not have the necessary clearances from local authorities, he said. 
 
 It was not immediately clear what caused the structure to collapse, but Raghuvanshi said the building structure was weak. Police were searching for the builders to arrest them, he said. 
 
 `'The inquiry is ongoing. We are all busy with the rescue operation; our priority now is to rescue as many as possible," he said. 
 
 Police with rescue dogs were searching the building, which appeared to have buckled and collapsed upon itself. Rescuers and nearby residents stood on the remains of the roof trying to get to people trapped inside. Residents carried the injured to ambulances and one man carried a small child caked white with dust from the wreckage. 
 
 Raghuvanshi said rescue workers had saved 15 people from the wreckage. 
 
 Building collapses are common in India as builders try to cut corners by using poor quality materials, and multi-storied structures are built with inadequate supervision. The massive demand for housing around India's cities and pervasive corruption allow builders to add unauthorized floors or build entirely illegal buildings. 
 
 Officials said the neighborhood where the building collapsed was part of a belt of illegal structures that had sprung up in the area in recent years. 
 
 `'There are lot of people involved (in illegal construction) _ builders, government machinery, police, municipal corporation _ everybody is involved in this process," G.S. Khairnar, a former top Mumbai official, told CNN-IBN television. 
 
 A local resident, who did not give his name, said the site was meant to hold a smaller structure and accused officials of turning a blind eye to the problem. 
 
 "They made an eight-story building of what was supposed to be a four-story building. People from the municipality used to visit the building but the builder still continued to add floors," he said. 
 
 In one of the worst recent collapses, nearly 70 people were killed in November 2010 when an apartment building in a congested New Delhi neighborhood crumpled. That building was two floors higher than legally allowed and its foundation appeared to have been weakened by water damage.
– At least 41 people have been killed after a building collapsed near Mumbai, the AP reports. More than 50 have been injured, and more could be trapped. At least 11 children were dead, officials said, with more than 20 people missing amid rescue efforts. The seven-story building was in the midst of illegal construction, the BBC reports, with four floors already occupied. The casualties were mostly construction workers who'd been staying in the building, said an official. "The building collapsed like a pack of cards within three to four seconds," said a witness. The disaster occurred as workers attempted to build an eighth floor, the AP notes. Building collapses are frequent in India thanks to weak materials and procedures, reports the BBC. High rises have been increasing in step with population increases, but they're often built without necessary safeguards and licenses. In this case, a witness said, "they made an eight-story building [out] of what was supposed to be a four-story building." Police intend to arrest the builders.