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INDIANAPOLIS, Ind. (March 17, 2015) – IPL engineers said Tuesday that the transformer below the sidewalk on Mass. Ave. was inspected in October 2014. Besides some minor rusting, engineers said there were no issues or anything to be concerned about until Monday night, when flames began shooting from a grate as people passed by on the sidewalks above.

“We last inspected that vault in October of 2014,” said Mike Holtsclaw, an engineer with IPL.

Holtsclaw said underground explosions caused by potentially faulty equipment, are dramatic but incredibly rare.

“I feel safe walking around downtown and being around this stuff. I think probably I’m at more risk driving into work every morning than I am walking around downtown Indianapolis,” Holtsclaw said.

“Certainly you’re not going to have your children walk over the top of something like that I mean obviously, it’s a concern,” said one woman, walking with her child on Mass Ave.

Mass Ave was packed with plenty of feet walking over what some here are calling, ticking time bombs.

“You can walk right on top of it to get room, I mean you have kids I mean, that could easily, wow, I didn’t even know that,” said another woman.

It was reported just before 9 p.m. Monday.

“Like a bomb or something,” said Mohammed Alshuwayi.

Alshuwayi lives right above the grate on Mass Ave, where the explosion took place, “When I heard the explosion, I thought something happened big, I thought you know a big explosion,” he said.

It was an IPL transformer that built up pressure and had a cover blow off, shooting steam and vapor from underground, to the sidewalk above, scorching and scaring passersby.

But this was not the first explosion in downtown Indy that IPL has had to deal with. Tuesday night’s marks the 14th explosion in the last ten years.

In August, a manhole explosion near the Circle City mall led to power outages and evacuations. Both Tuesday’s and August’s events occurred after a 2011 assessment of IPL’s underground grid. The Indiana Utility Regulatory Committee recommended IPL do a better job of inspecting its existing transformers.

There are more than 300 of transformers scattered around downtown Indy.  The faulty one that led to Tuesday’s explosion is out of commission and according to IPL will be replaced before the end of the week.

The transformer vaults, before 2011 were inspected every three years, they’re now inspected every two. The manhole covers, which also see similar underground explosions, are inspected every three years.

IPL officials said with all the events downtown, IPL crews are on always on standby in case an event were to occur, they’re able to handle it as quickly as possible.