`Dan Rather CBS building collapse`

Six-story Manhattan building under construction for CBS, early 1980s. Concrete beams with steel rebar; rebars were tack-welded where they crossed; high-carbon rebar at the tack-weld became brittle, fracture toughness dropped by a factor of eight, fifth-floor beam failed in bending tension, dominoed all the beams. $50 million loss, one workman's leg broken. The Steinway Piano factory tour (CBS-owned at the time) is a coda.