The gas leak which caused the Spencer Road area of the Waterside to be closed for a time yesterday appears to have been caused by an underground electrical fire in a cable, which released carbon monoxide gas.
Twelve people were taken to hospital as a precaution following the incident which saw a large number of fire appliances at the scene after the Northern Ireland Fire and Rescue Service received a report of a smell of gas at about 12.20pm yesterday.
One fire appliance from Crescent Link Fire Station and one from Northland Fire Station remained at the scene for more than two hours
PSNI officers helped throughout the incident to facilitate with the traffic disruption in the area.
Several business premises including a dental surgery and the Sandwich Company cafe were evacuated.
A spokesperson for the NIFRS said, “It is believed the electrical fire caused a release of carbon monoxide gas into the area.
“A number of people have been treated and a number of properties have been evacuated,” he said.