Power has been restored and residents have returned to their homes after a major natural gas leak in the south end of Halifax.

Police say construction crews contracted by Heritage Gas were performing routine maintenance work in the area of South and South Park streets around 9:30 a.m. when a main gas line was punctured, resulting in the release of active natural gas.

“It was a significant leak,” says executive fire officer Phil McNulty. “A two-inch gas line under pressure, when it’s punctured, releases that gas line under pressure. So, there’s quite a bit of gas that escaped into the atmosphere.”

“You could hear the leak,” says witness Dion Jean. “It was akin to a large exhaust fan blowing really hard, was the sound of it, and there was a slight mist in the air.”

Bill Swan, president of Heritage Gas, says the company was alerted to the leak at 9:45 a.m.

He says the punctured line is five centimetres in diameter and is the smallest line they have to service a residential neighbourhood.

Swan says he expects the broken line to be repaired by the end of the day and that eight to 10 Heritage Gas customers are affected by the leak.

“I’d like to say how sorry we are for the incident on behalf of our contractor,” says Swan. “Certainly very inconvenient and upsetting for all the local residents and I’m very sorry for that.”

Officials say the gas was shut off around 11 a.m. but they cordoned off several city blocks for several hours, saying it was too dangerous for anyone to go in or out.

More than 300 people were evacuated from their homes along South Park and Fenwick streets as a precaution and vehicle and pedestrian traffic were advised to avoid the area.

No daycares, hospitals or seniors residences were evacuated.

The areas bordering Tower Road to Queen Street and Victoria Road to Morris Street were closed to all traffic and several Metro Transit buses were rerouted.

Four air-conditioned Metro Transit buses were parked at different locations in the south end to give residents a place to relax and cool off. Police and area residents also handed out water bottles to evacuees.

Police say residents were told they could return to their homes at 2:30 p.m.

As a precaution, Nova Scotia Power shut off power to thousands of customers in the south end. At one point, over 7,000 customers were without power.

The power has since been restored to all homes and businesses in the area.

“The morning outage, unfortunately, took about three hours to be fully restored,” says Neera Ritcey, a spokesperson with Nova Scotia Power.

The power outage affected hospitals in the area; the Victoria General hospital site was operating on emergency power for about 90 minutes while the Halifax Infirmary switched to an alternate source of electricity.

Capital Health says all surgeries that were underway at the Victoria General at the time of the gas leak were completed and that operating rooms were then put on hold, resulting in the delay of 25 surgeries.

Power has since been restored to the hospital and officials say some of the affected procedures will go ahead today, while others may be rescheduled, depending on the length of time required to complete the surgery.

Health officials say affected patients will be notified if their procedure has been rescheduled.

Power was also shut down at the IWK Health Centre, which switched to a backup generator. Health officials say some surgeries were put on hold but none were cancelled.

The IWK’s emergency room and ambulatory services operated normally during the outage.

Regular power has since been restored to the hospital and all services are resuming as per usual.

“Once these massive incidents happen, we do notify the hospitals so that they can prepare if there is an influx of people, if people show up with some kind of intoxication from gas or whatnot,” says Halifax Regional Police Const. Pierre Bourdages. “At this time we have no reports of any injured people.”

The gas leak and subsequent power outage also inconvenienced local businesses; coffee shop owner AJ Son says he lost anywhere from $500 to $1,000 due to the incident.

“Not big, big money but I lost a lot of customers. That’s the biggest problem,” says Son.

City officials say some of the natural gas made its way into the Halifax sewer system but once the leak was contained, the gas dissipated. Tests indicate there is no way the gas would have entered Halifax Harbour.

Heritage Gas says it will be conducting a review of the incident.

With files from CTV Atlantic's Kayla Hounsell and Jacqueline Foster