As Philadelphia's most beloved Catholic saint, Katharine Drexel is said to have performed miracles by curing the sick.

A miracle of a lesser sort occurred Tuesday when a Philadelphia appeals board stunned preservationists and voted to spare the Church of the Assumption, the Spring Garden Street church where Drexel was baptized, from impending demolition.

The unanimous vote by the Licenses and Inspections Review Board effectively overturned a decision by the city's Historical Commission that would have allowed the church's current owner to raze the ochre building, which dates to 1848 and is the oldest surviving structure on a once-elegant boulevard.

The board issued its ruling in such a curt and deadpan manner that many people in the hearing room did not initially understand the implications of the vote.

"Incredible. I had no idea what was going to happen. That's amazing," Preservation Alliance director John Gallery said after learning that the board had reversed the demolition order.

Lawyer Kevin Boyle, who represents Siloam, the small nonprofit that bought the church in 2006, said in an interview later that he was "a little surprised" by the outcome. Siloam can appeal to Common Pleas Court, but Boyle said the group must study the board's "findings of fact" to determine whether a legal challenge is worthwhile.

The review board provided no explanation for its ruling.

Tuesday's vote by the review board was the second time the church has narrowly escaped the wrecker's ball. After Siloam began gutting the sanctuary two years ago, the Callowhill Neighborhood Association quietly filed papers to have the church designated as a historic building.

Demolition was halted, but Siloam pursued its case with the Historical Commission. It hired an engineer, who reported that the church's tapered, copper-clad spires were structurally unsound.

Siloam filed a new demolition request, this time citing financial hardship. The nonprofit, which provides free medical care to people with AIDS, complained that it was unable to sell the church, and said repairs could run to $1.5 million, more than its annual budget.

After a lengthy and contentious hearing in September, the Historical Commission agreed, 6-5, to let Siloam take down the church. That's when the Callowhill neighbors asked the L&I board to take a look.

The neighborhood association argued that Siloam never seriously tried to market the old church, near 12th Street. During the March hearing, several members of the review board also remarked that Siloam's efforts to sell the building appeared halfhearted. The church had been listed for sale only a few months when Siloam requested the demolition permit.

At the same hearing in March, a representative from the Clay Studio testified that the studio was eager to buy the building and establish a gallery and studio complex.

Andrew Palewski, the Callowhill resident who nominated the church for historic status, said the board's unanimous vote on Tuesday "goes to show the Historical Commission made the wrong decision."

Leonard Reuter, the lawyer for the Historical Commission, declined to comment about the board's decision.

Although the church lost some of its grandeur when Siloam gutted the interior, Palewski said he thinks the building could still be a catalyst for a neighborhood revival, especially if it is sold to an arts group.

There are at least two major development projects in the works on Broad Street, including a food emporium in the former Wilkie Buick building two blocks to the west as well as several smaller projects closer to the church. The Callowhill area is where booming Northern Liberties merges with Center City.

"Yes, they have to do things to fix the building," said C. Anne Anderson, a member of the Callowhill board who attended the hearing. "But it would be a great addition to the neighborhood."