Seems like a decision was made, repeatedly, to do nothing about it, while knowing it was an issue.

https://www.maritime-executive.com/article/hezbollah-denies-...

> Former port worker Yusuf Shehadi confirmed this account to The Guardian on Thurday. In his recollection, "30-40 nylon bags of fireworks" had been stored in the same warehouse as the cargo of ammonium nitrate for many years. Port workers and customs officials were well aware that both of these consignments were on site and potentially dangerous, and they had raised the issue multiple times, he said. “Every week, the customs people came and complained and so did the state security officers. The army kept telling them they had no other place to put this. Everyone wanted to be the boss, and no one wanted to make a real decision," Shehadi said.