A caporegime in the Stracci Family, the other being Oscar Zavarelle.
However, in 1946, Grossi's explosives business began to fail due to the death of one of his explosives transporters, Plinio Ottaviano. After this he fled to Trapani's Bakery in Little Italy . Here, Grossi was ambushed and thrown into the oven by enforcer Aldo Trapani.
Leon Grossi was known for his savvy in matters of business and finance. He gained his money from the Stracci Family's explosive racket that was run through his soldati, Kyle Bellini.