Chris Hitopoulos was just weeks away from opening a new salon inside her renovated Spring Street house downtown Tuesday when a welder's torch accidentally melted a gas service line beneath the house, igniting a fire that burned for more than two hours.

Hitopoulos could only watch as gas-fed flames licked the front of the 170-year-old house at 101 Spring St., even as firefighters poured hundreds of gallons of water on the blaze to keep it from spreading.

The fire was finally extinguished about 2 p.m. when South Carolina Electric & Gas crews dug into the road using a jackhammer and found a valve that shut off the service line at the main line.

When it was over, the front of the building was scorched and warped from the water and flames.

"It's really an incredible building and this is the saddest thing," Hitopoulos said while standing across the street.

She hired Archer Construction to completely renovate the house that, a year ago, was dilapidated with leaning porches. The salon was planned for downstairs with two rental apartments on the second story.

Construction was about a week and a half from being finished when authorities say a welder beneath the house accidentally melted the gas line while attempting to install a waterline. The welder was unhurt.

A man who didn't want to be identified said he could hear gas hissing from across the street. He then heard a small pop and saw the flames.

Officials with Archer Construction said they were still trying to determine what happened. All of the utility lines were marked and the gas to the house was shut off. Officials estimated the line was about 50 years old.

Even though there was no gas coming to the house itself, the service line at the street was still on, said Trish Freshwater, public affairs coordinator for SCE&G.

Firefighters shut down two blocks of Spring Street and told people in neighboring homes and in businesses across the street to stay inside, said Mark Ruppel, public information officer for the Charleston Fire Department.

Hitopoulos said she still plans to finish the project, despite the setback.