Which of the following statements is CORRECT?

An arson attack in the northern Mexican city of Monterrey has left at least 53 people dead. Gunmen burst into the building in broad daylight, dousing it with fuel and setting it alight. Fire crews had to free dozens of people trapped by smoke and flames. Officials suspect organized crime was behind the attack, one of the deadliest since President Felipe Calderon launched his crackdown on the Cartels in December 2006. (6) State police officials quoted survivors as saying gunmen had burst into the premises and tried to rob it, before emptying fuel from tanks they had brought with them. Officials said those inside had hidden in toilets and offices when they heard explosions instead of trying to get out and had suffocated as smoke engulfed the building.