How do you grieve for a building?

The many supporters of Walker Community United Methodist Church -- churchgoers, neighbors, activists and friends -- gathered Monday to mourn and celebrate a place that has been home to different causes and faiths for 100 years.

The Rev. Walter Lockhart guided his congregation through a sometimes somber but mostly joyous makeshift prayer service. Just a few hours earlier, its tight-knit members watched as the historic structure in south Minneapolis quickly burned down. Only the church's sign stands.

The remains of the building were torn down by city crews before the end of the two-hour service, which was held a few blocks away at Living Spirit United Methodist Church. As more than 100 people filed into her church, the Rev. Donna Dempewolf praised Walker's progressive ministry and the congregation's resiliency. Bishop Sally Dyck of the Minnesota Area of the United Methodist Church and Twin Cities District Superintendent Liz Lopez called Walker Church a "symbol of community" in the Powderhorn Park neighborhood.

"The building is gone, but the people are the church," said Lockhart, bleary-eyed from lack of sleep and a few shed tears. "What we have before us is a new journey."

Prayers and gratitude were offered to the five firefighters injured in the blaze. Two firefighters remain hospitalized with non-critical injuries. Three other firefighters were released from the hospital.

Authorities haven't determined what caused the fire, but Minneapolis Fire Chief John Fruetel said indications point to lightning. He said a bystander saw a flash on the west side of the church, just before a smoke alarm dispatched city firefighters to the scene.

He said that because the building had to be torn down Monday, the cause may never be proved. "I think it was a natural cause."

"It was difficult to locate the fire," Fruetel said. Some firefighters went to the attic looking for a source of the smoke. Suddenly, "the fire exposed itself," he said. "There was a rapid flame spread that rolled across the ceiling and conditions changed very quickly." All injured firefighters had first- or second-degree burns, he said.

Fire displaces tenants, too

The fire has displaced not just the congregation, but the many human and social rights groups that rented space there. Walker Church has been a gathering place for activist groups. In recent years, the church has lobbied for issues ranging from immigration to gay rights.

Among the groups it hosted was Occupy Minneapolis, which has been staging demonstrations against income disparity, the nation's largest banks and home foreclosures.

Communities United Against Police Brutality has rented an office on the top floor for seven years, said president Michelle Gross. Other groups with office space were Minnesota Immigrant Rights Action Committee and the Welfare Rights Committee. The Anti-War Committee held regular meetings there.

Gross said that during the month of Ramadan, Walker allowed a Muslim group to gather in the basement every night to worship. KFAI radio and In the Heart of the Beast Puppet and Mask Theatre started at the church before moving into their own facilities.

"It is definitely a blow to activist groups," said Osha Karow, of Occupy Minneapolis. "But it is an opportunity for people to come together to figure out the next steps and what they can do to help out Walker."

An emergency meeting held Monday afternoon drew 85 people, mostly activists, to decide what to do next.

"I've said for a long time, 'What would we do without Walker Church?'" said Dave Bicking, a longtime activist. "Now we are going to find out."

Amid loss, some celebrated what felt like a miracle -- survival of the church's altar box.

Kristine Smith said she and others had gone over after the morning service to see the damage. Someone saw a corner poking from under charred timbers and broken bricks. The box was a good 20 feet from its usual resting place, she said.

It survived flames, fire hoses and bulldozers with only a few scrapes to its black paint. An abalone shell used in ceremonies was broken. But a menorah, an altar cloth marked with yin and yang and a set of Tibetan tingsha bells were fine.

"We were bemoaning their loss this morning," Smith commented. "But they've come home. Now they're sacred. The fire made them sacred."

Staff writer Maria Elena Baca contributed to this report. 612-673-4465 • 612-673-7382