Banff residents are not able to call 911 after phone and cellphone coverage dropped in the mountain town west of Calgary.

Officials say those who have emergency should go to the Banff Fire Hall or Mineral Springs Hospital.

But the power is back on in Banff and Lake Louise after a flooded transformer failed, knocking out the lights in the two resort communities for a few hours late Saturday and into early Sunday.

People reported hearing a loud noise that sounded like an explosion at the substation.

However, TransAlta spokesperson Stacey Hatcher said there was no explosion — instead, the transformer was flooded when the plant tried to release excess water into an emergency spillway.

Instead of following the spillway, Hatcher said the water backed up into the facility and flooded the transformer.

No one was injured in the incident, but the flooding knocked out power to Banff and Lake Louise. It also forced officials to temporarily close roads in the area.

TransAlta said its crews, with the help of teams from CP Rail, Fortis and Altalink, have repaired the damage at its Cascade facility in Banff National Park.

With files from The Canadian Press