An underground electrical fire near the intersection of First and Main streets this morning has caused traffic snarls and power outages around downtown."It was really black and thick, you know, just like your typical electrical material plastics burning. And it was coming out with force," said Captain Salvador Melendez, public information officer for Louisville Fire Department.The fire happened around 7:30 this morning in Louisville Gas and Electric’s system. The issue is not to be confused with problems related to the sewer system, like initially reported by bystanders, said Melendez."We don't want people thinking that your sewer system is about to explode," he said.LG&E Spokeswoman Chris Whelan said the company still isn’t sure what caused the fire.“It is an electrical malfunction and it is in our underground system so it’s a little bit more difficult to get down to repair,” she said. “You have to get materials and everything down in a manhole and the work is kind of tedious. But it is electrical equipment and when you have that you’ve got to expect that there could be malfunctions," Whelan said.Melendez said the fire department was able to isolate the issue and has tested the underground environment to ensure its safety for workers.Several traffic lights in the area weren’t functioning, and Whelan said many of LG&E’s downtown customers are without power.“It affected about 368 of our customers and we have already started to isolate the situation and get a few of those customers back on,” said Whelan.She said she expects power to be restored in phases. The ones nearest the incident will be the last to come back on, but she expects most to be restored sometime late today.Also, the grid does not necessarily provide power continuously to businesses along its route, said Melendez."Five blocks from here there's a couple of businesses without power and that's because of what's going on here," he said.The area near the fire has been evacuated and nearby streets have been closed. Traffic is being routed around First and Main, and a number of other intersections are closed, including First and Market, Second and Market, and Third and Market.Louisville Fire Department has 18 firefighters on scene working with LG&E throughout the day.Its unclear when the problem will be fixed. LG&E expects to work throughout the day but is unsure if traffic will be cleared by rush hour.