Yep, a five gallon can of gas, two padlocks and a bic lighter would have been far deadlier weapons than a rifle. And anyone can buy all of those things at just about any Wal-Mart.
Strap some jerry cans to the front of a rental car and just ram the front door.
https://en.wikipedia.org/wiki/Happy_Land_fire
The Happy Land fire was an arson fire that killed 87 people trapped in an unlicensed social club named “Happy Land”, at 1959 Southern Boulevard in the West Farms section of the Bronx in New York City on March 25, 1990. Most of the victims were young Hondurans celebrating Carnival,[1] largely drawn from members of the local Garifuna American community.[2][3] Unemployed Cuban refugee Julio González, whose former girlfriend was employed at the club, was arrested soon afterward and ultimately convicted of arson and murder.
The Happyland Cub fire in NYC was started in just such a manner.
...Unlike most of the nightclub fires we will see on this list, the Happy Land fire was started by an act of arson.
However, like so many other nightclubs, the Happy Land building was an unlicensed “social club”, was built with combustible and flammable materials, had previously been closed for fire safety violations, and the fire exits had been blocked to prevent people from entering without paying.
The fire started at the “Happy Land” located in New York City, on March 25, 1990. The fire killed 87 people, 68 on the second floor, and the rest on the first floor. Eleven people were killed inside a first floor restroom.
Most of the victims were ethnic Hondurans.
The fire was started by an unemployed Cuban refugee named Julio González, who was upset at his former girlfriend (who worked at the club). As a result of the argument, González was ejected by the bouncer. Angry, he came back to the club with gasoline which he spread on the only staircase into the club. He then used matches to ignite the gasoline. The fire quickly spread to the combustible material used in the entry way, and then spread from the entry way into the first floor bar through a door someone had left open.
Unlike so many nightclub fires, the Happy land building did have a partial sprinkler system on the second floor, but not all of the sprinkler heads activated and regardless, the sprinkler system was inadequate to contain and control the fire, which started on the first floor...