SPRINGFIELD, Ohio — A nearly 300-foot smokestack being demolished at an old Ohio power plant top-pled in the wrong direction and sent spectators scrambling Wednesday before knocking down two 12,000-volt power lines and crashing onto a building housing backup generators, officials said.

No injuries were reported after the 275-foot tower at the unused 83-year-old Mad River Power Plant teetered and then fell in a southeast direction — instead of east, as originally planned — seconds after explosives were detonated.

The falling tower brought down the power lines and sent spectators scrambling to avoid the sparking lines.

“It just started leaning the other way and I thought, ‘Holy cow’ ... It was terrifying for a little bit,” Springfield Township Fire Chief John Roeder told the Springfield News-Sun.

Officials estimated that about 4,000 customers in the Springfield area, about 25 miles northeast of Dayton, lost power because of the downed lines.

Lisa Kelly, the president and owner of Idaho-based Advanced Explosives Demolition Inc., which handled the demolition, told the News-Sun that the explosives detonated correctly, but an undetected crack on the south side of the tower pulled it in a different direction.

“Nobody’s happy with things that go wrong in life, and sometimes it’s out of our hands and beyond anybody’s prediction. ... We’re all extremely thankful no one was injured,” Kelly told The Columbus Dispatch.

Officials say the debris landed on the FirstEnergy property.

“We had it all planned out. Everything was scoped out ... it caught everybody by surprise,” Tim Suter, FirstEnergy’s manager of external affairs, told the News-Sun. “Everybody was kind of excited, looking for cover.”