When the smoke had settled and the reality set in, Micha’s Mexican Restaurant’s owners and family members saw a glimmer of hope in the restaurant’s remnants.

The shrine that for years greeted diners at the entryway of the South Tucson restaurant, 2908 S. Fourth Ave., was unscathed. No water or smoke had touched the painting of founders Gilbert and Artemisa Mariscal, or the photographs of their son, Richard, and other long-gone employees and family members that made up the shrine.

“I thought that was beautiful,” said Richard Mariscal’s namesake, son Richard, who no longer works for the family business. “The roof fell in on one side, but the outside structure stayed up.” Family members on Monday said they would rebuild the 42-year-old restaurant, but it’s anyone’s guess when.

Most of the details still needed to be ironed out, said Lorraine Mariscal, who runs the restaurant with Deborah Martinez.

“It’s not safe to go inside,” she said in between back-to-back phone calls Monday as she pieced together how to begin the process. “I know we’re going to rebuild.”

South Tucson Fire Department investigators have ruled the fire’s cause as undetermined, although they believe it started near the grill or oven.

“There wasn’t anything that we noticed that was out of the ordinary,” said South Tucson Fire Capt. Andy Luna. “Everything looked normal, like a closed restaurant.”

Luna said when firefighters came on the scene just after 10 p.m. Friday night, all they saw was smoke coming from the building.

It wasn’t until they got inside that they discovered fire in the kitchen and that part of the roof had collapsed.

“At that point, everybody realized, ‘Oh my goodness. This historic building, the family,’ “ said Luna, who grew up in South Tucson. “It was pretty horrific.”

Luna said the loss of Micha’s was still dominating conversations around town on Monday.

Micha’s was the first restaurant when you turned onto the avenue, which is lined with longtime family-owned Mexican restaurants.

Luna said his department’s investigation is complete. Building inspectors will examine the extent of the damage once they determine the structure is safe, and when they are done, insurance investigators will take over.

Contact reporter Cathalena E. Burch at cburch@tucson.com or 573-4642. On Twitter @Starburch

I cover music for the Arizona Daily Star.