It was around 8:45 a.m. Tuesday when Norristown firefighters were called out to the 100 block of Main Street for the report of a fire.
When crews arrived on the scene they found smoke coming up from the sidewalk.
PECO says contractors were doing some improvement work when a worker digging hit a wire that caused a short and sparked a fire.
Sparks went all the way around the corner to a Dunkin Donut, causing a fire to break out on the inside and outside of the building.
A worker was burned and taken to a hospital for treatment. So far, there are no other injuries reported.
The faulty wires caused a carbon monoxide leak to send gas into several of the businesses which forced evacuations along the street.
Crews were able to contain the leak and PECO shut off the electricity to the businesses so they could start repairing the underground wires.
Officials say the street will be closed for the rest of Tuesday and probably into part of Wednesday.