By 1820 throwing was done on rectangular frames and the width of the building was dependent solely on the strength of the floor beam.

After the floor beams were installed, at alternate floor beam panel points a set of diagonal bracing struts were installed.

The basement fire, burning through a supporting floor beam., caused a section of the floor to drop into the basement as it rushed up into the main level.

Cast-iron was used for the roof trusses and floor beams.

The plane parts destroyed three floor beams, and severely compromised the building's internal structure.