Authorities found a body inside a burned-down building in North Hills on Thursday after a three-day search, authorities said.

Investigators haven’t identified the person, and it’s not clear how they died. Authorities are working to remove the body while fire operations continue into Friday, according to a news release from the Los Angeles Fire Department. Crews are trying to demolish the rest of the structure.

The discovery was made after two dogs from the Los Angeles County Sheriff’s Department detected “human bone or tissue” in the area of the burned-down structure, which was previously a church, in the 15200 block of West Parthenia Street, according to the Los Angeles Fire Department.

On Tuesday, firefighters responded around 5:43 p.m. to a fire in a commercial building, according to an LAFD news release. The blaze was threatening a neighboring four-story apartment building, so commanders ordered firefighters to defend it, the department said.

A total of 27 people, including six adults and 21 children, were displaced by the fire, officials said.

Paramedics evaluated three people, and two women were hospitalized in fair condition, according to the release.

Three of the 41 units in the apartment building were yellow-tagged, authorities said.

The Los Angeles Department of Transportation provided DASH buses as temporary shelter for displaced residents while the city’s housing authority and the local chapter of the American Red Cross helped with food and relocation needs.

While firefighters were evacuating residents from the apartment building, other crews were sending water into the burning building, which wasn’t extinguished until the roof collapsed and crews could hit the flames directly. The fire was extinguished in less than two hours, according to the release. The LAFD Arson and Counter-Terrorism Section is investigating the cause of the fire.

Edward Viramontes told ABC7 that he thought he knew how the fire started.

Viramontes, who lives in the adjacent apartment building, saw a woman hunched over something two hours before the fire started. He also saw sparks. The woman reportedly jumped over the fence after the blaze started.

Viramontes shared the photo he took of the woman with arson investigators.

“I just grabbed all my kids, threw over the stroller, and I just ran out the house,” he told the TV station.