Points Gang was one of the country's first major organized crime entities. As Italian immigration grew in the early 20th century many joined ethnic gangs, including Al Capone, who got his start in crime with the Five Points Gang. The Mafia (also known as Cosa Nostra) first developed in the mid-19th century in Sicily and spread to the East Coast of the United States during the late 19th century following waves of Sicilian and Southern Italian emigration. Lucky Luciano established Cosa Nostra in Manhattan, forming alliances with other criminal enterprises, including the Jewish mob, led by Meyer Lansky, the leading Jewish gangster of that period. From 1920–1933, Prohibition helped create a thriving black market in liquor, upon which the Mafia was quick to capitalize. New York City as a whole experienced a sharp increase in crime during the post war period. The murder rate in Manhattan hit an all time high of 42 murders per 100,000 residents in 1979. Manhattan retained the highest murder rate in the city until 1985 when it was surpassed by the Bronx. Most serious violent crime has been historically concentrated in Upper Manhattan and the Lower East Side, though robbery in particular was a major quality of life concern throughout the borough. Through the 1990s and 2000s, crime in Manhattan plummeted in all categories versus historic highs. Today crime rates in most of Lower Manhattan, Midtown, the Upper East Side, and the Upper West Side are consistent with other major city centers in the United States. However, crime rates remain high in the Upper Manhattan neighborhoods of East Harlem, Harlem, Washington Heights, Inwood, and NYCHA developments across the borough despite significant reductions. In more recent years there has been an increase in violent crime, particularly in Upper Manhattan and NYCHA developments. Housing During Manhattan's early history, wood construction and poor access to water supplies left the city vulnerable to fires. In 1776, shortly after the Continental Army evacuated Manhattan and left it to the British, a massive fire broke out destroying one-third of the city and some 500 houses. The rise of immigration near the turn of the 20th century left major portions of Manhattan, especially the Lower East Side, densely packed with recent arrivals, crammed into unhealthy and unsanitary housing. Tenements were usually five stories high, constructed on the then-typical lots, with "cockroach landlords" exploiting the new immigrants. By 1929, stricter fire codes and