MUKILTEO — Arson is the cause of an early morning fire that destroyed a church building next door to Kamiak High School, fire and police officials said. No one was injured in the blaze.

The Snohomish County Fire Marshal’s office, the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, and Mukilteo Fire and Police departments concluded Saturday afternoon that the fire was started outside near the back entry of the Church of Jesus Christ of Latter-day Saints building at the corner of Harbour Pointe Boulevard and Chennault Beach Drive.

The two-alarm fire, first reported shortly before 3 a.m. Saturday, has left two Mormon congregations without a place to worship.

Firefighters at the nearby Mukilteo Fire Department responded within minutes, said Assistant Fire Chief Brian McMahan.

“The fire may have been burning for a couple hours before someone even noticed it and alerted 911,” McMahan said. “We called for the second alarm just minutes after we arrived on the scene.”

Initially, flames and smoke were seen inside the building. Firefighters had to cut open a gate into the church campus to bring in trucks and equipment. By the time crews began fighting the fire, the flames had burned through the roof.

More than 44 firefighters from Mukilteo, Lynnwood, Everett and Fire District 1 worked to get the fire under control. The church is a total loss, McMahan said. The building’s value was assessed at $1.6 million, according to information found on the Snohomish County Assessor’s Office website.

Because the church building was unoccupied, crews fought the fire defensively, limiting risk to the safety of the firefighters, said McMahan. On Saturday afternoon the fire continued to smolder and the roof and walls of the building continued to collapse. No one was allowed inside, he said.

Evidence of arson has been collected and the Mukilteo Police Department is in charge of the investigation, McMahan said.

The church, at 11001 Harbour Point Blvd., was built in the late 1980s before fire and building codes written in the mid-1990s required sprinkler systems. The one-story building, which included a gym, also did not have fire alarms, the lack of which could have allowed the fire to spread unchecked for at least two hours before it was detected, McMahan said.

Serena Stucki, who lives nearby, said she heard what sounded like fireworks just after midnight. Stucki stopped by the fire scene on Saturday to let officials know what she had heard.

Dennis Butterfield, a Mill Creek volunteer with Fire Support 7, helped provide refreshments to the firefighters and shelter to the church officials who watched the fire from the sidewalk.

“The flames were burning high, and the crews were going like crazy,” butterfield said.

Jeff Lee, president of the Lynnwood Stake of the Church of Jesus Christ of Latter-day Saints, was among those who watched for hours.

The fire affects two wards under the Lynnwood stake: the Harbour Pointe and Beverly Park wards. Together, more than 800 people in the wards are displaced by the fire, Lee said. For now, the wards will double up with others in the area, Lee said.

“We will rebuild and move on,” he said. “There is the initial shock and sadness because many of us have good memories of events there. But in the end, it’s just a building.”

Gale Fiege: 425-339-3427; gfiege@heraldnet.com.