The 275-foot tall smoke stack was supposed to fall toward a dirt area but instead it fell toward power lines and two power-generating buildings.
About 50 people who were watching the implosion were caught near those power lines.
"As soon as that large boom went, you could see it start to sway the wrong way. Just kind of start to sway. Then it went down quick and everyone started yelling, 'get out of the way! Run! Run! Get out of the way!" Samantha Sommer said.
Demolition crews say an unknown crack in the smoke stack caused it to fall the wrong way and that no one would have been able to make it fall correctly.
About 4,000 people briefly lost power because of the incident.