Gun Control & RKBA

Unlike modern ammo, black powder is volatile. That's why there are federal regulations on its storage: how much, what conditions, etc.

The article doesn't say what started the fire, nor does is say what the man died of. Certainly firefighters would be at risk if there were still large quantities of unburned black powder on the premises -- one of the reasons for the regulation. But exploding ammo typically just sends the brass case flying a short distance and is not deadly. Cartridges must be tightly enclosed in the chamber of a gun for them to generate sufficient force to send bullets flying.