A grease fire in the ventilation system of Casper's Good Cooking caused about $50,000 worth of damage to the popular diner, Casper Fire-EMS said Friday, and the restaurant remains closed.

The fire broke out about 7 p.m. on Thursday and forced about 15 to 20 customers to evacuate into steady snow and freezing temperatures.

Firefighters arrived to find flames and smoke coming from the roof of the Poplar Street building. They managed to put it out within 15 minutes, but they remained for about two hours to ensure the fire was completely extinguished, according to a fire department news release.

No one was injured in the blaze.

A passing police officer first noticed the fire and evacuated the building. As they were evacuated, the occupants weren't aware of the fire, according to the release.

Casper's remained closed Friday and a reopening date has yet to be determined, according to restaurant staff.

"We are hoping as soon as possible," said waitress Toni Pompura.

An insurance adjuster still needs to visit the restaurant and kitchen equipment must be replaced, she added.

"Right now, it is completely up in the air," she said.