Federal investigators concluded Wednesday that the controlled fire in Pacific Palisades, and officials hope to help them determine what caused the January fire to kill 12 people and destroy thousands of homes.

Nearly four months after the U.S. Alcohol Bureau, tobacco, guns and explosives began investigating fires in Palisade, investigators set fire to burn parts of the Temescal Ridge Trail between Skull Rock and Green Peak from Tuesday night to Wednesday morning.

Los Angeles Fire Captain Erik Scott announced Wednesday that the ATF “has fire tests conducted on the Tescal Ridge Trail in the Santa Monica Mountains.”

"A systematic post-test drill confirmed that all materials were cold and extinguished. The ATF and the City of Los Angeles Fire Department would like to thank the public for their collaboration in these operations," Scott said.

According to the ATF, fire testing is expected to take place until Thursday. The results of the test were not immediately revealed.

Investigators have been trying to determine the exact origin of Palisades Fire and how it competes from the mountains to the ocean in a massive storm.

"The flame position, the flame size helps," said ATF's agent Matthew Beals. "It's like reversing. You try to bring it back to a reasonable level of scientific certainty."

Officials believe the Palisade fire was found around 10:30 a.m. on January 7 because strong winds caused the flames to race on dry terrain. Sources familiar with the investigation show that most of the focus is that fireworks sparked eight acres of fireworks a week ago, and firefighters believe they have been put out in the same area.

On January 1, a resident reported that the Rahman fire broke out about 12:17 on the hillside of Palisade in the Pacific, and its house was about two blocks from the popular Skull Rock Trail. Sources of the investigation that were not authorized to speak publicly told the Times that the Rahman fire appeared to be caused by fireworks.

Just over three hours later, fire officials reported that they stopped the fire from advancing.

Assistant Fire Chief Joe Everett, who helped oversee West Bureau of Lafd, including Pacific Palisades, said firefighters had a cold tailing surgery at the site, and the crew felt waving any lingering heat along the edge of the fire, digging out every attraction, digging out every place, and digging trenches on the edge of the fire to ensure there is no explosion in the future.

Investigators have not ruled out that the fire was triggered on the morning of January 7. In either case, sources said the cause of the fire could be due to humans because there are no telephone poles near the place of origin and the trail area is wide.

Without a reason, some homeowners sued the Los Angeles Department of Water and Electricity, claiming that the utility failed to properly prepare for the wildfire and responded to the outbreak.