KOLKATA (India) • Residents clawed with their bare hands to try to rescue people pinned under a 100m-length slab of metal and cement that snapped off at one end of a flyover in bustling Kolkata and came crashing down on vehicles and street vendors below.
Television footage from the scene showed a bloody hand reaching out from under what appeared to be a girder and the bloody legs of trapped people jutting out of the collapsed girders and concrete slabs.
"Everything is finished," screamed Ms Parbati Mondal, whose fruit-seller husband was missing in the collapse.
The accident is the latest in a string of deadly construction collapses in India, some of which have highlighted shoddy building standards. A huge demand for housing, roads and other infrastructure in India often results in cost-cutting and a lack of safety inspections.
As the death toll surged to at least 20, with over 75 injured and up to 150 people feared trapped in the rubble, police and pedestrians used their hands to try moving fallen girders to reach buried survivors.
"Most were bleeding profusely," said senior police officer Akhilesh Chaturvedi of the injured, noting that traffic jams were hampering rescue efforts. "The problem is that nobody is able to drive an ambulance to the spot."
Soldiers rushed to the site, as people raced to the scene with bamboo poles to lift rubble and crowds gathered in the hope of hearing news of loved ones feared trapped.
Specialist rescue teams armed with concrete cutters, drilling machines, sensors to detect life and sniffer dogs were on their way, said National Disaster Management Authority spokesman Anurag Gupta.
Two buses carrying more than 100 passengers were believed to be trapped. Eight taxis and six motorised rickshaws were partly visible in the rubble.
An injured builder at the scene said that he had been working on the structure before it collapsed and had seen bolts come out of the metal girders.
"We were cementing two iron girders for the pillars, but the girders couldn't take the weight of the cement," said Mr Milan Sheikh, 30, before being taken away to hospital. "The bolts started coming out this morning and then the flyover came crashing down."
Construction on the 2km-long flyover began in 2009 and was supposed to be completed within 18 months, but the project suffered a series of hold-ups.
Video footage showed a street scene with two motorised rickshaws and a crowd of people suddenly covered by falling concrete that narrowly missed cars crawling in a traffic jam.
Other visuals showed concrete mixer trucks, cargo carriers and yellow taxi cabs under twisted steel beams and huge concrete slabs.
"The area was very, very crowded. Motorised rickshaws, taxis... There was a lot of traffic," one witness told NDTV , the New Delhi Television news channel.
Chief Minister Mamata Banerjee, whose centre-left party is seeking re-election next month, rushed to the scene. "We will take every action to save lives of those trapped beneath the collapsed flyover. Rescue is our top priority," she said.
Ms Banerjee, 61, said that those responsible for the disaster would not be spared. However, she herself faces questions about a construction project that has been plagued by delays and safety fears. A newspaper reported last November that Ms Banerjee wanted the flyover - already five years overdue - to be completed by February. Project engineers expressed concerns over whether this would be possible, The Telegraph said at the time.
Indian company IVRCL was building the 2km Vivekananda Road flyover, according to its website. Its Idirector of operations A.G.K. Murthy, said the company was not sure of the cause of the disaster.
"We did not use any inferior quality material and we will cooperate with the investigators," he told reporters in Hyderabad, where the company is based. "We are in a state of shock."
Another company representative, Mr K.P. Rao, called the disaster an "act of God", a remark already receiving harsh criticism.
REUTERS, AGENCE FRANCE-PRESSE, BLOOMBERG