The Pantheon's interior was highly embellished with ornamental plaster, draperies and painted details such as the birds of paradise.

Interior finishes include molded ornamental plaster and marble with cast-iron detailing.

Designs in ornamental plaster have changed little through the years, Mr. Martorella said.

And as their framework was constructed of ornamental plaster they could not be taken down for repair.

The church was built in the Italian Renaissance style, with extensive marble, rich ornamental plaster and towering twin spires.

And a 15-foot section of ornamental plaster has fallen away from the first balcony, like flesh removed from a skeleton.

Peeling paint hangs in great sheets; ornamental plaster is shed into the void.

Sunlight filtering through a hole in the roof touched the scant ornamental plaster still in place.

The damage was restored with amongst others ornamental plaster and ceiling paintings.

Decorators Supply, in Chicago, makes hand-cast ornamental plaster; www.decoratorssupply.com or (773) 847-6300.