An investigation at the site of a North Hills vacant church fire that erupted Tuesday evening and reignited the next day uncovered a body inside the charred building.

Crews fought the fire at the boarded-up church for nearly two hours on Tuesday before they were finally able to extinguish the massive flames that engulfed the building. The blaze was first reported at around 5:45 p.m. in the 15200 block of W. Parthenia Street, according to the Los Angeles Fire Department.

They said that the two-story commercial building, which is believed to be vacant and the former spot of a church, was showing heavy fire when they arrived. The flames were threatening the neighboring four-story apartments, prompting crews to work through each floor to evacuate residents. Firefighting efforts resumed Wednesday morning after flames and smoke were visible from the charred structure.

Cleanup of debris was underway on Thursday morning as heavy equipment cleared a portion of the destroyed structure so crews could complete their recovery investigation. Los Angeles Fire Department Capt. Erik Scott said that during a preliminary investigation, a human remains detection K-9 unit made an identification.

"It made a hit, which indicates that they found either bone tissue or blood and that could be a body, or blood from a cut hand," he said. By Thursday afternoon, fire investigators reported that a body had been found.

More than 100 firefighters were assigned to the blaze on Tuesday as crews attacked in defensive mode, meaning that they were battling the flames from above and outside due to the possible danger posed by the structural integrity, which eventually saw the roof of the building collapse. They determined the incident a Major Emergency as their battle continued.

With SkyCal over the spot of the fire, massive plumes of black smoke could be seen extending into the sky. Flames could be reaching from the right side of the structure in the alleyway next to the apartment building while dozens of people looked on.

At around 7:20 p.m., an updated LAFD release said that crews were "more effectively able to reach the deep-seated fire," and were making good progress on extinguishing the flames. They said that the fire was finally extinguished at around 7:40 p.m., nearly two hours after their firefight began.

They said that some windows of the apartment building were broken and that they were still assessing the damage to the part of the structure that was exposed to the fire. They said that three of the complex's 41 units were yellow-tagged, displacing six adults, 21 children and six pet turtles.

One person, a 42-year-old woman, was treated at the scene for possible smoke inhalation before she was taken to the hospital in fair condition, firefighters said. The cause of the fire remains under investigation by LAFD Arson investigators.

On Wednesday afternoon, LAFD officials said that "out of an abundance of caution," a team of human remains detection K9s was brought to search the debris of the structure.

"They showed interest in an area that could not be safely investigated by firefighters," the latest update from LAFD said. "An alert does not necessarily mean a body was located which is why visual confirmation is required."

They noted that the operation could last for several days, especially as crews were on hand to strategically demolish the structure so debris could be cleared.

Tatiana Guerrero is a good Samaritan who said she rushed into the burning building to help a woman yelling for help from the second floor.

"When I saw the building on fire, I saw a girl that was yelling for help," she said. "I tried to get as high as I could with her, I just grabbed her and I had to throw her down on the floor. The fire was literally in back of her."

Guerrero said that she then ran into her apartment building and pulled the fire alarm, alerting other residents so they could get out safely.

The Los Angeles Department of Building and Safety has been called to assess the building's structural safety. If it is red-tagged, they said that LAFD Heavy Equipment operators will evaluate the building for possible demolition.

Other residents said that the place was inhabited by homeless people, despite being boarded up. Firefighters said it's a possibility they're investigating as to the cause of the fire.

Julie Sharp contributed to this report.

A fire that tore through a vacant church in the San Fernando Valley on Tuesday was still actively burning Wednesday morning, forcing evacuations at a neighboring apartment complex and displacing families as firefighters continued battling hot spots and flare-ups.

More than 100 Los Angeles firefighters were sent to the blaze at 15226 W. Parthenia St. in North Hills around 5:43 p.m. Tuesday after heavy flames erupted inside the boarded-up two-story building, which sits directly next to a four-story apartment complex. Crews remained on scene overnight and into Wednesday as smoke continued to drift over the area.

The building has been red-tagged as unsafe, and LAFD said heavy equipment crews will evaluate whether it must be demolished to protect nearby homes.

Families, children and pets displaced

While the apartment building did not suffer major structural damage, the Los Angeles Fire Department said three of the 41 units were yellow-tagged, meaning they were temporarily unsafe to occupy.

That forced the displacement of six adults, 21 children and six pet turtles, according to fire officials.

The Los Angeles Department of Transportation provided DASH buses for temporary shelter, while the Housing Authority of the City of Los Angeles and the American Red Cross Los Angeles Region responded to assist with food and immediate relocation needs.

One resident, a 42-year-old woman, was taken to a hospital in fair condition for possible smoke inhalation and shortness of breath. No firefighter injuries were reported.

Neighbor says he saw the fire start

Edward Viramontes, who lives in the apartment complex next to the building, told KTLA he believes he witnessed the fire being set.

Viramontes said he was inside his home with his four young children when he saw a woman near the wall where the fire began.

“That was the person that caused the fire,” Viramontes said. “She made the fire. I witnessed it going out of control. I barely had time to grab my kids and run.”

He said the vacant building had long been a problem with people squatting inside.

Demolition possible, investigation underway

Firefighters said the roof collapsed during the fire, allowing crews to better reach flames deep inside the structure.

The building has since been red-tagged, and LAFD heavy equipment operators will assess it Wednesday for possible demolition if it is deemed a continued hazard.

LAFD arson investigators are now working to determine what sparked the fire.

Roads closed, smoke still drifting

Parthenia Street between Noble Avenue and Kester Avenue remains closed as firefighters continue monitoring the scene for flare-ups.

Drivers are urged to avoid the area, and residents nearby are advised to keep windows closed until the fire is fully extinguished.

Omar Lewis contributed to this report.

More than 100 firefighters put out a blaze at a two-story building Tuesday in Los Angeles that prompted evacuations, according to authorities.

The Los Angeles Fire Department responded around 5:43 p.m. in the 15200 block of West Parthenia Street in North Hills 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 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 under two hours, according to the release. LAFD Arson and Counter-Terrorism Section is investigating the cause of the fire.

Edward Viramontes told ABC7 that he thinks he know 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 person 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.

NORTH HILLS, LOS ANGELES (KABC) -- More than 100 Los Angeles firefighters battled a large fire at a vacant two-story building that forced residents in a neighboring apartment complex to evacuate.

The fire was reported around 5:43 p.m. Tuesday in the 15200 block of Parthenia Street in North Hills, according to the Los Angeles Fire Department. It took crews just under two hours to report a knockdown.

Most people who live in the nearby complex have been allowed to return to their homes. Three units have been yellow-tagged, meaning tenants can access their belongings but they can't stay there.

A total of 27 people - six adults and 21 children - are temporarily displaced.

Huge plumes of smoke billowed from the vacant building as crews battled the blaze from a defensive position. While firefighters worked to contain the flames, they also evacuated residents in the neighboring four-story apartment complex.

The thick smoke was enough to trigger the apartment building's fire alarms.

"I was waking everybody up, like, 'We gotta get out of here,'" Gysselle Ramirez said.

Edward Viramontes said flames covered the outside of his window and even caused a crack in the glass.

"I just grabbed all my kids, threw over the stroller, and I just ran out the house," he said.

Viramontes thinks he saw that fire as it sparked.

Two hours earlier, Viramontes says he snapped a picture out his window looking toward the abandoned building. He said the photo shows a woman hunched over something. Then, he says, there were sparks.

He said he saw the person jump over the fence as the fire erupted. He shared the photo he captured with arson investigators.

A 42-year-old woman in the apartment building was taken to a hospital in fair condition to be treated for possible smoke inhalation, according to LAFD.

Another woman suffered a panic attack at the scene.

The fire caused some broken windows in the apartment complex. Firefighters checked the apartment building for any further damage.

Firefighters remained at the scene throughout the night to extinguish any hot spots left.

LAFD arson investigators are looking into the cause of the blaze.