The small flashes don’t look like fireworks shells — little delay and no blossoms.
I’s say they were ammo rounds cooking off as blown into the air.
A whole lot of people looking out their windows at the time are hurting now.
Hezbollah controls the dock. Heavy weapons ammo storage and rocket manufacture. They were likely pumping diesel out of one of the two ships tied alongside probably the small one which was blown on shore. AN needs an accelerant like diesel to ignite.
Fire started in the “fireworks” storage warehouse, shell penetrated adjacent warehouse igniting the stored AN and rocket motors.
Yep..... not fireworks