On Friday, the Minneapolis Fire Department held a news conference discussing Tuesday’s deadly apartment fire.

On Thursday, fire crews were alerted to one resident in the building who was unaccounted for and returned to the to search the scene. They discovered two bodies in the rubble.

Minneapolis Fire Chief Bryan Tyner said when they responded to the fire, it started as an offensive procedure, with firefighters searching units of the apartment and battling the fire from the inside.

However, Tyner said it soon became apparent that the roof of the building was going to collapse, and the strategy was shifted to defensive, which prevented fire crews from finishing their primary search as they were not able to check the top floor of the apartment building.

Initially, on Tuesday, fire officials said that three people — two adults and a child — were being treated for burns, and another adult was treated for smoke inhalation. All four victims were said to be in serious but stable condition.

“Although we were able to rescue a number of residents, tragically we discovered yesterday that we were not able to rescue them all,” Tyner said at the press conference.

Tyner said two fire victims were discovered Thursday, a woman and a man, both under debris in the same apartment unit on the top floor. Neither victim has been identified yet. Friday’s search found no additional victims.

“I would like to express my sincere condolences to the family and friends of the victims of this tragedy,” Tyner said. “I pray that you find comfort in the coming days.”

Tyner said one of the toughest parts of being a firefighter is that not everyone can be saved. He also expressed his support to the incident commander who made the decision to change strategies on Tuesday.

“It’s an incredible, difficult decision to make,” Tyner said. “But if he had not we would likely be here talking about deceased firefighters in addition to the tragic loss of these two victims.”

Tyner said the investigation is ongoing, and no cause for the fire has been determined yet.