Shops were evacuated in Newquay town centre on Saturday after a manhole burst into flames.
The electrical fire happened in Fore Street outside Razzamatazz and Admiral Casino at about 5pm.
Eyewitnesses heard cracking noises before the blaze started.
A makeshift barrier made out of plastic chairs was put in front of the fire before the emergency services arrived.
Cornwall Fire and Rescue Service and the police attended the incident.
There were dramatic scenes as firefighters shop workers were led to safety as loud booming noises could be heard.
Fore Street was cordoned off to pedestrians and vehicles from Chapel Hill to Alma Place.
Some of those evacuated were taken to the Sailors pub.
Eyewitness Jo Booth said: "Electric was intermittently on and off in Fore Street.
"Then smoked billowed from a man hole cover and it set alight.
"Police and fire engines came to the scene."
Sailors Night Club and Pub opened on Saturday night despite Fore Street being closed off.
A spokesperson said: “We are still open in as usual however as Fore Street is closed, please visit us via Beach Road.”
Read more about the incident in next Wednesday's Newquay Voice.