A sequence of events that included a malfunctioning jack and over-extended scaffolding may be to blame for the partial collapse of a Westfield Montgomery Mall parking garage that killed one person, according to a new report.

The report from KCE Structural Engineers, obtained by the Washington Post, call the event a “tragic construction incident” that occurred after a sequence of events.

A “safety” tower wide flange header beam began to fall (twisted)

In an attempt to rectify the situation, [a Whiting-Turner crew] re-jacked the tee up and was in the process of removing the slightly twisted steel section

A jack/pump assembly may have malfunctioned

The “jacking” tower scaffold legs were extended beyond manufacturer recommendations and extension sections were not braced per manufacturer requirements

Carroll Dexter Willis, 57, was killed after a 43,000-pound slab on concrete fell 18 inches. Another worker was seriously injured.

Montgomery County officials will meet with Whiting-Turner, according to the Post.