WARREN, Mich. – Officers investigating a weekend house explosion that critically injured a suburban Detroit man found multiple bombs, weapons and thousands of rounds of ammunition inside the man’s home.

Warren Police Commissioner William Dwyer says the 38-year-old man lost both his arms in Saturday afternoon’s explosion and was in a coma at a hospital.

Dwyer said Sunday that investigators believe the man was working on a explosive device when it exploded.

First responders reported the explosion took place in the home’s garage, and a fire then spread into the two-story house. Dwyer says the man is being investigated for manufacturing illegal weapons inside of his home.