I appears from other sources that the explosion occurred in a primer components mixing station.
We had a similar incident occur at a plant here many years ago 51 years ago. Surviving family members claim the components at that incident were difficult to pump thru piping and their soon to be deceased son was attempting to clear the line. I won't repeat what they claim he was doing.
My dad - Korean veteran - was eating lunch, looked up, and remarked he heard something - 21 miles away.
Regardless of the time and place, primer mix is a very delicate composition which does not tolerate mishandling. For those who might consider the manufacture of it at home due to long term availability under extreme economic conditions, think again. There is a reason why ammo plants have component assembly buildings separated by thousands of feet with enclosed transfer hallways stretching in between, located in remote areas with thousands of acres surrounding them. The plant located near here is between two towns with little to no agricultural development and zero housing startups for miles. If it should ever shut down their will be an avalanche of builders bid up the properties.
However, at present Dyno is operating a demil plant with incinerator and things try to remain quiet in that operation. It's punctuated with an occasional explosion none the less.
About 8 miles due west is a fireworks storage facility and when we hear out of season detonations it's always a guessing game if it was an intentional burn off or another person got killed again. The last time two trailers disappeared in what was later deemed a static discharge transferring merchandise.
The two workers also disappeared.
Just part of life around here.
