Two 100-metre-high residential towers collapsed with a loud thud into a huge cloud of dust in Delhi’s satellite city Noida on Sunday, marking a rare legal victory against illegal construction by India's big developers. The Apex and Ceyane buildings, commonly called the "Twin Towers", crumbled in less than 10 seconds as 3,700 kilograms of explosives were detonated to carry out the Supreme Court's demolition order. The developer Supertech began constructing the towers inside an existing housing complex more than a decade ago. However, it was forced to stop work in 2011 when residents of the area filed a lawsuit claiming the buildings breached municipal laws. Hundreds of people had gathered to witness the demolition in Noida, about 25 kilometres south-east of <a href="https://www.thenationalnews.com/world/2022/08/15/indian-pm-modi-pledges-to-develop-nation-on-75th-independence-day/">New Delhi</a>, as police struggled to keep onlookers outside a 500-metre, cordoned-off safety zone. The crowd cheered and booed as a massive explosion shook the ground and the towers came down crashing at 2.30pm local time. Ram Bir, 36, said he came from nearby Greater Noida city to witness the “historic” demolition, but also questioned how they were built in the first place. "We are here to see how these huge buildings will crash down, but I am curious how these towers could be erected if they were illegal. What was the government doing?” he told <i>The National</i>. People also watched from the balconies and terraces of buildings and other vantage points. "This is the first time I have seen something like this. I was both scared and excited," said Siraj Ansari, who witnessed the demolition from a nearby bridge. The demolition was carried out after authorities evacuated nearly 7,000 residents from nearby buildings and posted hundreds of police and emergency workers in the area. Stray animals were also removed, and the area was declared a no-fly zone for 30 minutes during the demolition. Buildings around the Twin Towers were covered with geotextile fabric to protect them from damage. Officials said the demolition left nearly 60,000 tonnes of concrete debris and a cloud of dust 60 storeys high. More than 100 water tankers and smog guns were used to control the dust and air pollution. Some of the debris will be used to fill in the basements of the towers. The demolition was carried out with about 3,700kg of explosives packed into about 10,000 holes drilled into the buildings. The final checks began at noon on Sunday, before the explosives were charged for detonation. Utkarsh Mehta, chief executive of Edifice Engineering, the company that carried out the demolition, said it would be "like a waterfall, so that it will slowly and steadily will come down to the ground and the impact and vibration would be reduced”. Some media reports said the demolition had partially failed as parts of the towers did not fall as planned and landed next to a residential complex. Officials said residents were to be allowed back into their homes later on Sunday after engineers assessed the situation and defused any leftover explosives. The demolition is one of the biggest carried out so far in a country that has a chronic problem of illegal construction. Four luxury high-rise apartments were demolished with explosives in the southern Kerala state in 2020 after they were found to be built in an environmentally sensitive zone. Construction on the Twin Towers was halted in 2011 after a legal challenge by residents of the housing complex where they were being built. The residents said the buildings breached the site plan because the land had been earmarked for a garden, and complained that they also blocked air and sunlight to hundreds of existing dwellings. The Allahabad High Court in Uttar Pradesh ordered their demolition in 2014, a ruling that was upheld by the Supreme Court in 2021. Court documents showed that Supertech, which also built the existing residential complex, had colluded with authorities to construct the towers. In a statement released shortly before the demolition, Supertech said the towers had received proper permissions but were ordered demolished on technical grounds. "The building plans of the project including the two towers were approved by the Noida Authority in 2009, which was strictly in accordance with the-then prevailing Building Bye-laws announced by the State Government," the company said. "However, the Hon'ble Supreme Court has not found the construction satisfactory on technical grounds and accordingly issued orders to demolish the two towers. We respect the orders of the Apex Court and are committed to implementing the same." The Supreme Court has ordered the developer to refund payments from buyers of homes in the towers, together with 12 per cent interest. The developer must also pay 20 million rupees (about $250,000) to the residents’ welfare association of the housing complex.