If you're afraid of being in a bank during a bank robbery, don't go to the bank on Friday mornings between 9 a.m. and 11 a.m.
Banks used to have more money on a Friday because it was historically a payday. Also, bank robbers believed that there's more money in the bank at the beginning of the day rather than the end. Interestingly, banks in the supermarkets are actually safer than a regular bank branch. (Source)
The Largest Bank Heist in History
The largest bank heist in history occurred in 2003, when nearly $1 billion was stolen from the Central Bank of Iraq just hours after US bombed Baghdad in the Iraq War. The culprit was Saddam Hussein and his family. Only about half of the money was recovered (source).
The First U.S. Bank Robbery
The first bank to be robbed in the United States was the Bank of Pennsylvania. The vault was robbed of $162,821 ($1.8 million in 2006 dollar) in 1798.
Because there was no sign of forced entry, the authorities believed that it was an inside job (locks on the vault's door was just changed). The blacksmith that changed the lock was Pat Lyon, who left Pennsylvania to escape a raging yellow fever epidemic that swept Philadelphia. Lyon suspected that a carpenter was responsible, and went back to Philly to clear his name. The authorities didn't believe him and threw him in the Walnut Prison.
The culprit turned out to be someone who earlier had visited Lyon's shop, named Isaac Davis. He and a partner (an inside man, the bank porter who later died in the epidemic) pulled off the heist but did something monumentally stupid: he started to deposit his stolen money back in the bank! Confronted by the authorities, Davis confessed and gave back all the money. As part of a plea deal, he never served a day in prison.
Even after that confession, the authorities refused to release Lyon. Later, charges against him were dismissed and Lyon sued the bank and law officials. He got $12,000 (a large amount at the time) for false imprisonment.
Pat Lyon at the Forge by John Neagle (1892)
Pat Lyon, who became a hero after his trial, was immortalized by a painting by John Neagle titled Pat Lyon at the Forge. If you look closely, there's a cupola of the Walnut Prison in the background.