After being badly damaged in a fire in 1909, the interior and roof were rebuilt under the supervision of architect John T. Comès and the church was rededicated in 1910.

The Pittsburgh Gazette Times reported:[10] The electric bolt struck the church at 6:15 o'clock [p.m.] between the two huge towers and shattered the immense organ in its descent.

A cloud of smoke arose and in a few seconds flames broke from the huge front memorial window and shot out into the street fifty feet.

[3][14] In 2022, a feasibility study commissioned by ELDI concluded that the church could be viably renovated as a multi-purpose events space for a cost of about $15 million.

[15] Saints Peter and Paul was designed in the Gothic Revival style and is attributed to Adolphus Druiding, of Chicago, while local architect John T. Comès was responsible for the 1910 reconstruction.

Suehr wrote,[1]: 62–65 The notable improvements on the exterior consist largely in removing many of the galvanized iron crockets and crosses from the towers and gables, and especially the enormous tower crosses, all of which made the front appear restless and 'overbusy,' in the changing of the old large Gothic top wooden window to a stone rose window 20 feet in diameter; in the new gable over it and the omission of useless pinnacles on each side; finally in the new broad steps and wide walk with two Gothic piers, which give the building a solid looking base and a dignified approach.Inside, the original wood and plaster columns were replaced with stone and the wooden roof was replaced with steel and reinforced concrete.