Why did a Dominican nightclub roof cave in?

SANTO DOMINGO, Dominican Republic (AFP) -- The government of the Dominican Republic has vowed an exhaustive investigation into why the roof of a nightclub caved in on revellers, killing more than 200. Experts, meanwhile, said the causes appear to be clear: insufficient support for too heavy a structure also weakened by a fire almost two years ago. Video footage of the last moments before the roof of the Jet Set club came crashing down in the wee hours of Tuesday showed people leaving the venue in ...