"Initially, video taken by residents showed a fire raging at the port, sending up a giant column of smoke, illuminated by flashes of what appeared to be fireworks. Local TV stations reported that a fireworks warehouse was involved. The fire then appeared to spread to a nearby building, triggering a more massive explosion, sending up a mushroom cloud and generating a shock wave."
https://apnews.com/d6503f7d779f2790218fe29121368788
