Here is the 1987 stock market crash as set-up by the weekly bar chart of the S&P500 cash index.
The market crashed right on time and right back to the price levels from the massive 21-week consolidation at 235.
The market also failed to make a new high for 5-weeks and then the price fell below the mode since the high, which was at 320. The market also sliced through the previous mode at 289 (marked in purple) where most likely people were covering short positions against that . However, once through 289, there was no stopping the market until it fell back down to major, long term support at 235 (and a bit below).
You can see how extended the market was at the highs - it was extremely overbought.
Tim 2:27PM EST Wednesday March 26, 2014