WATERVILLE – The cause of a downtown fire that destroyed one building and damaged two others last week is undetermined, investigators said Monday.

“The fire did originate from a third-floor deck, but the damage was too much to definitively say what caused it,” said Sgt. Tim York of the State Fire Marshal’s Office.

York also said a sprinkler system in the building had been turned off but he had no information about why that happened. John Weeks, the landlord and owner of 18 Main St., did not return a call for comment Monday.

The fire started around 4 p.m. Friday and destroyed the top two floors of the four-story building at 18 Main St. The rest of the building was damaged by water and smoke, according to Waterville Fire Chief David LaFountain. It originally was thought to have been a cooking-related fire that started on a grill outside a third-floor apartment. LaFountain said he had no more information on the fire Monday and that the investigation had been slowed because state fire officials were responding to fires in Lewiston.

Meanwhile, tenants in two of the buildings damaged by the fire continued to clean up and recover from the disruption. The fire also damaged 16 Main St. and the back of the Silver Street Tavern, which contains three apartments and is owned by Charles Giguere, according to LaFountain.

Six employees from the INK-4-LIFE tattoo shop, formerly located at 18 Main St., gathered on Monday afternoon at the home of Bill and Mona Juliano.

The shop will move into the former Levine’s clothing store, across the street from 18 Main St., the site of their former shop, the Julianos said. They plan to reopen by June 1.

“I’m just so excited. I was there today pulling up the old floor,” said Mona Juliano, 38, of Benton.

She said the employees of the store are like her family and that they were devastated by the fire.

“It was our life. It was everything we do,” said Brian Frampton, 33, of Skowhegan, a tattoo artist at the shop. He said he is excited about the new store.

“I’ll be there tomorrow. I can’t wait,” he said.

The former Levine’s is owned by Michael Soracchi, a Connecticut businessman who bought the building in January with plans to renovate it as housing and retail stores. INK-4-LIFE is expected to be the first business in the building, and Soracchi said he hopes others will follow.

The main entrance will be on Front Street, but the shop will also have a back entrance on Main Street, he said.

Sorrachi said he was glad he could help the displaced store owners and their employees find a new location.

“It’s scary to not have a place to go to work on Monday. Currently their business is shut down, and that’s not good. It’s a hardship on their families,” he said. He said he is interested in investing in Maine real estate and already owns three properties in the state.

“It could really work out nicely. We were worried about INK-4-LIFE and are thrilled that we will not be losing a downtown business,” said Jennifer Olsen, executive director of Maine Street Waterville, a nonprofit dedicated to advancing the development of the downtown area.

Other tenants also worked on the recovery process Monday.

January Wiltshire, 37, lives on the second floor of the apartments in back of the Silver Street Tavern. The damage to the building was mostly on the second and third floors, she said, including a window on the second-floor hallway that was burned.

Wiltshire said her apartment was filled with soot over the weekend. She wasn’t home when the fire started, and firefighters had to break through her door to get water to the other building, she said.

The fire also damaged a window in the kitchen of her upstairs neighbors, she said.