The Buffalo Propane Explosion: What Happened?

What I saw there I will never forget.
At 20:23 hours, on December 27, 1983 the Buffalo Fire Department responded to a reported propane leak in a four-story warehouse at this corner of North Division and Grosvenor streets (46 Grosvenor St). What happened next shook the city, literally... I went there that night... This is what I remember.