[RoyalsFan]

No it wasn't. It was killed by a moron who decided that hurling a "firecracker" (most likely an M-80) into the backyard of a relative was a good idea.

The article says the firework was legal. That means it couldn't have been an M-80, those were banned in 1966.

[Mr. Mojo]

Hard to imagine that a standard little firecracker could kill a Jack Russell. It probably had the maximum legal limit of 50 mg of flash powder. Many such firecrackers are sold under the name "M-80" even though they're not the real McCoy.