The biggest bank robbery of all time was identified in Brazil in 2005. In this case, a gang broke into a bank by tunneling through 1.1 meters of steel and reinforced concrete and then removed 3.5 tons of containers holding bank notes. This heist resulted in the loss of about 160 million Brazilian dollars (US$380 million).
Source: http://www.symantec.com/connect/blogs/tiylon-modern-bank-robber Christian Tripputi