Fireworks are a lot of fun. Sure not everyone's thing but many enjoy them and can manage to use basic safety and not endanger anyone.
I just can't believe a firework going off right at an airport was not intentional. I believe someone was most likely thinking "I'm gonna lite this off right by a plane for all to see my awesome show!". Not trying to hit the jet but rather just look at me people isn't this awesome!? No it is not.
This is the type of thing that ends up getting fireworks banned or more controlled for the rest of us.
Reminds me of the idiot who flew his drone over an active forest fire while crews were actively fighting it causing the helicopters or water bombers to have to disengage the fire until the drone was gone. Then drone rules get tightened for the average guy just wanting to have fun responsibly.