They do this all over America
Not unique to Philadelphia
I remember visiting some Nam buds in New York city
in the 1970s on the Fourth of July.
It sounded like Nam and the streets were an inch deep
in shredded chinese news print. One of my friends lived
on the edge of Harlem and we got into duels with the people
in the street, us throwing M-80s off the roof and the
brothers shooting at us with roman candles.
Good times.