The Pittsburgh Millennium Creche on U.S. Steel Tower Plaza costs $55,000 each Christmas season to assemble and disassemble, and its endowment is down to $102,000.
If after 13 years this is not to be its last, the Diocese of Pittsburgh will have to raise money.
The Rev. Ron Lengwin, a spokesman for the diocese, said the endowment "lost a good 50 percent of its funds" after the economic crisis of 2008. "We were forced to draw from the corporate side and just couldn't keep going back to the same people."
The creche, which is sponsored by the Christian Leader's Fellowship, is the world's only replica of the Vatican Nativity. Approval for the replication was granted by the Vatican at the request of architect Lou Astorino, who had designed a chapel in Vatican City where he saw the original creche.
"There's no way that creche is going away," Mr. Astorino said. "We will raise money."
Most of the work on the Nativity is donated -- from electricians, carpenters, scaffolding, storage and the crane and its operator -- Father Lengwin said. Nuns sew new costumes every year for all the life-sized figures.
But not all the labor is free, and other costs include truck rentals and police service. The Nativity scene also suffers some damage most years, largely due to weather, and needs to be repaired.
The scene, which includes a stable, weighs 60 tons.
Father Lengwin spends his evenings at the site, he said, "because I love it and want to make sure everything is OK. And it's the perfect place to be during the Christmas season."
To passers-by, he has been the expert voice, with answers and brochures about the creche. He also has supplied his own collection of traditional Christmas music.
"There was a time when homeless people used to come in the morning, at 2 or 3 o'clock, to listen to the music and look at the images," he said. "They would tell the guards about how it reminded them of how life used to be different for them when they were children. It was one of the places they could go and not feel as if they were unwanted.
"There have been at least two wedding proposals at the scene and wedding parties that have come to have pictures taken. People would talk about the days they remember when families were closer and what a joy it was for them."
The scene is all the more dramatic this year, he said, "with Occupy Pittsburgh right across the street. The creche is a visual service to people experiencing poverty," a connection to Jesus, who was born into poverty himself.
The Rev. Donald Green, executive director of Christian Associates, helped with the initial endowment fundraising. He said the position of the creche, on private property as a public display, "makes it very unique beyond its being a Vatican replica. It is a place people come to out of pious devotion. It would be a tragedy to not be able to maintain it."
Donations can be made for the creche in care of the Diocese of Pittsburgh, 111 Blvd. of the Allies, Pittsburgh, PA 15222-1618.