Explosion Could Become a "Cold Case"

Authorities are still searching for the source of a mysterious underground explosion that ripped through the sewer lines beneath a quiet neighborhood near River Hills Drive and Highway 13 East.

“I’ve never had anything like this happen in my career. I’ve never even heard of it,” said Fire Chief B.J.  Jungmann. “I’ve heard of sewer explosions, of course, but I’m not aware of anything like this. It’s really odd.”

The explosion occurred on , when residents reported a series of blasts and rumblings that tossed 100 pound manholes eight feet into the air and blew the exhaust stack of the roof of a house. No one was hurt during the incident, but at least 100 residents were evacuated.

Many neighbors complained of a distinct smell of gasoline shortly before and after the explosion. On arrival, emergency workers found dangerously high levels of carbon monoxide in the sewer lines, up to 1,000 to 1,200 parts per million. At the time, Fire Marshal Lee LaTourelle said it was possible that somewhere in the system an incomplete combustion produced the onslaught of CO.

For over a week, both Burnsville Fire and the public works department have tried to ferret out the source of the blast. However, much evidence of the explosion has gone down the drain, quite literally.

“We can't point to anything right now. We don’t have a good answer,” Jungmann said. “The hard part of the whole deal the majority was down the drain as we got there. There’s stuff moving through that line all the time so it’s tough to find anything after the fact to track anything down.”

Jungmann said there have been no recurrences of the strange phenomenon, though the department will continue to monitor the sewers just to be safe.

Jungmann offered some general safety tips to residents who may be wary.  First, don’t just water your garden, water your basement floor drain as well.

“They should be making sure they have water in their traps and drains in floor. That’s how sewer gases can get up (into the house),” Jungmann said.

Otherwise, Jungmann advised residents to report any unusual chemical smells.

“That's all they can do,” Jungmann said. “They should call us if something doesn't seem right.”

Anyone who might have additional information about the incident on July 8 should call fire administration at 952-895-4570.

 “This might be a cold case we just keep on the backburner,” Jungmann said. “We may never know, but well keep monitoring for another week or so.”