A fire broke out at the San Gabriel Mission early Saturday and burned the roof and much of the church’s interior, officials said.

Authorities have not determined what caused the blaze at the 249-year-old church on 428 S. Mission Drive.

The San Gabriel Fire Department received a call about the fire at around 4:30 a.m. and arrived at the scene to find flames through the roof, Capt. Antonio Negrete told KTLA.

The crews called for additional units after about 5 minutes, Negrete said. Some 50 firefighters responded to the location, and they struggled as parts of the roof began to come down, according to the captain.

“The fire traversed the wood rapidly, the interior is pretty much destroyed up into the altar area,” Negrete told the Associated Press.

Workers had just redone the walls and refinished the 107-year-old pews as part of a renovation project ahead of the church’s 250th anniversary next year, San Gabriel Mission spokesperson Terri Huerta said. The roof last underwent repair after sustaining damage from the 1994 Northridge earthquake, she added.

“To see it being burned down is just heartbreaking,” Huerta told KTLA.

But an altar piece that dated back to the original mission was still intact, she said.

“There’s a lot to be grateful for that didn’t burn in the fire,” Huerta said.

Video recorded before daylight Saturday shows dark smoke rising from the flames. Negrete said firefighters continued to battle the blaze hours after the initial call.

In an 8:25 a.m. tweet, the Police Department announced shutting down Junipero Serra Drive and Mission Drive in both directions between Ramona Street and Clary Avenue due to “police and fire activity.”

The crews appeared to have extinguished the fire by 11 a.m. Officials did not report any injuries.

San Gabriel Mission set up a fire restoration fund to help rebuild their church.

The church, founded in 1771, was the fourth of 21 missions established by the priest Junipero Serra, according to the Los Angeles Times.

In previous weeks, statues of the priest who worked to convert Native Americans to Catholicism in the 18th century and forced them to say in missions have been removed across Southern California, including at the San Gabriel church.

The statue had stood outside the San Gabriel Mission since the 1980s but the church relocated it out of the public’s view, citing activists’ toppling of Serra’s statues across California, a statement from Father John Molyneux said.

“Whereas the California Catholic Conference of Bishops reminds us that the historical truth is that St. Serra repeatedly pressed the Spanish authorities for better treatment of the Native American community, we recognize and understand that for some he has become a symbol of the dehumanization of the Native American community,” Molyneux said. “We at Mission San Gabriel are committed to continuing dialogue with our Native American representatives in order to achieve a peaceful and just partnership.”

The Fire Department said what ignited the fire remains under investigation, and that it’s unclear whether it’s suspicious in nature.

Correction: A previous version of this story provided an incorrect first name for Capt. Antonio Negrete. This post has been updated.