Inflatable roof collapses at American football stadium as 20 INCHES of snow is dumped on Midwest in ONE DAY

By DAILY MAIL REPORTER Deflated: Holes in the collapsed Metrodome roof can be seen in Minneapolis after a snow storm dumped 17 inches on the cityFour people killed as gigantic winter storm rips across the upper mid-WestMore than 1,600 flights cancelled as 2ft snow falls in 24 hours and temperatures plummet to -18CBlizzard warnings across Iowa, Wisconsin, Illinois and MichiganMajor highways