Several versions of the story say construction accident, several others say "accident at a construction site" ...
The only one that seems to have the details is one from WIVB-TV/Buffalo (quoted by a sister station in my
link) who quoted his mother who they interviewed
The 36-year-old had been on life support after suffering complications from a workplace accident. ... Williams’ on-the-job accident last month was not immediately thought to be life-threatening. Rosenthal said Williams was doing electrical work when someone above him dropped a steel beam that struck Williams in the head. He thought he had walked away from the incident with just a headache, but his symptoms worsened that week.