As Moscow\'s legendary chandeliered underground fills with water, thousands of terrified commuters flee through flooded tunnels in a disaster movie that has topped Russia\'s box office. The film, titled simply \"Metro\", depicts what might happen if Moscow\'s Stalin-era underground system, which last year carried more than two billion passengers, sprung a leak from the Moscow River flowing above it and a speeding train crashed into a wall of water. Filmed in a genuine metro system -- albeit in the Volga city of Samara, not Moscow -- the film looks disturbingly realistic, from the boxy blue carriages to the clunky monitoring equipment that simply loses all contact with the train. \"Can you imagine what\'s going on down there?\" asks one petrified employee. The film topped Russia\'s box office in its first weekend, comprehensively beating action hero Arnold Schwarzenegger\'s comeback movie \"The Last Stand\". It has now earned $9.7 million, according to preliminary figures released by Variety Russia magazine. The film\'s budget totalled $13 million, including a $6 million grant from a state fund designed to promote national cinema. The real Moscow metro is rich with legend, from the giant cockroaches that allegedly roam its tunnels to secret lines said to lead from the Kremlin. Its ornate decor includes talismans such as the bronze dog at the central Revolution Square station whose nose has been rubbed bright by constant pats for luck. Muscovites associate recent genuine horrors with the metro, including deadly suicide bombings in 2004 and 2010 as well as a harrowing accident in 2006 in which a pile being driven into the ground for an advertising hoarding pierced through a shallow tunnel. Well-heeled Muscovites make a point of never descending into the metro -- even though that means sitting in traffic jams for hours on end. The film plays on latent fears about the crumbling network, but the director dismissed the idea that it could upset survivors of militant bombings. \"You see, if you argue like that, we couldn\'t make World War II movies, we couldn\'t make any films because they will always somehow touch people who had the experience,\" said director Anton Megerdichev at a press conference. Unsurprisingly perhaps, Moscow metro\'s management were not keen on the film, banning the crew from filming in its stations. Undeterred, production was moved to Minsk, the capital of Belarus, only for a deadly metro bombing to strike there in April 2011 as the crew were due to start filming. Finally they went to Samara, around 1,050 kilometres (652 miles) south of Moscow, whose little-used metro system proved only too authentic. \"The most interesting thing is that it\'s wet. It drips everywhere, we didn\'t need to add any computer graphics. They constantly mop and wipe those stations, so basically it was perfect for us,\" the director said jokingly. The film stars Sergei Puskepalis, best known for his lead role in 2010 BFI London Film Festival winner \"How I Ended Last Summer\". He plays a surgeon taking his daughter to school on the metro who finds himself in the same carriage as his wife\'s lover, a go-getting property developer, who has descended reluctantly into the network, having been stuck in a giant traffic jam above ground. \"Can I charge my mobile phone anywhere?\" he asks one bewildered plebeian passenger. The plot centres on the doctor\'s rivalry with the smart-suited but brutal lover, who casually chucks a Yorkshire terrier into the rising water around their metro carriage to check whether the live rail is switched on. But the film\'s real star is the water: all nine tonnes of it, which slops around a dark tunnel, sometimes rising in giant waves, sometimes reaching almost to the ceiling. Russian critics hailed the film as a rare attempt to make a homegrown disaster movie, a Hollywood genre that has barely hit Russian screens since the 1979 Soviet film \"Air Crew\". \"Russian cinema has broken through,\" Vedomosti business daily headlined its review. \"Metro is an amazingly well-crafted film, with every stage of the catastrophe well founded and constant moments of suspense -- oh God, when the water reaches the live rail!\" wrote Afisha magazine.