Bugsy Siegel (1906–1947) was a founding member of Murder, Inc. and the visionary gangster who helped transform Las Vegas into a gambling mecca. He oversaw the construction of the Flamingo Hotel and Casino in 1946, though cost overruns and delays made him enemies within the mob. He was murdered in his girlfriend's Beverly Hills home in 1947, just months after the Flamingo opened.

Reference:

Bugsy Siegel on Wikipedia

https://en.wikipedia.org/wiki/Bugsy_Siegel