The basilica burst into flames and its roof was completely destroyed, as well as many of the interior artworks. No one was certain whether the fire had been caused by a careless workman or by political arson. Some thought that it should be redesigned to accommodate the changing times; but the pope said no – it should be restored to its former glory.

Is this the story of the Cathedral of Notre Dame? Nope – I’m talking about the Basilica of St. Paul Outside the Walls, one of four ancient papal basilicas. The other papal basilicas, all located within the walls of Vatican City, are St. Peter’s Basilica, St. John Lateran, and St. Mary Major. In contrast to the others St. Paul Outside the Walls, as its name implies, is located outside the Vatican’s Aurelian wall, within Italian territory; but it remains the property of the Vatican and enjoys full diplomatic immunity, just as a foreign embassy has immunity as guaranteed under International Law.

 

A Long History of Innovations and Expansion

The Basilica of St. Paul Outside the Walls was originally erected by the Emperor Constantine I early in the fourth century and stood directly above a memorial, called a cella memoriae, which marked the burial place of the Apostle Paul. Years later, in the 370s, it was expanded under the reign of Valentinian I. Emperor Theodosius I erected a much larger basilica in 386, featuring a nave and four aisles. Included were priceless mosaics which were finally completed during the pontificate of Pope Leo I, who led the Church from A.D. 440 to 461. When two Christians from nearby Ostia Antica, Saints Taurinus and Herculanus, were martyred in the fifth century, the basilica became known as the “basilica trium Dominorum” (the basilica of Three Lords).

The work continued: Pope Gregory the Great modified the nave, raising the pavement so that the altar sat directly above St. Paul’s sarcophagus. The new design permitted access to the sepulcher where Paul’s remains (excluding his head) were buried. But then in the ninth century, the basilica – which was not protected by the Vatican walls, as were the other papal basilicas – was badly damaged during the Saracen invasions. Worried that the church could be subject to future invasions, Pope John Paul VIII (872-882) ordered that the basilica and the nearby monastery be fortified. The town of Joannispolis was formed, incorporating the basilica and surrounding buildings behind tall walls; but the town was completely destroyed by an earthquake in 1348.

 

The Tragic Fire and the Historic Restoration

On the night of July 15, 1823, the Basilica of St. Paul Outside the Walls was nearly destroyed by fire. It was thought that perhaps a careless workman, repairing the leaden roof, had permitted the fire to get its start.

But the Church was determined to restore the basilica to its former glory, and it was re-opened in 1840 and reconsecrated in 1855, with Pope Pius IX and 50 cardinals in attendance.

Many countries contributed to the reconstruction effort: the Viceroy of Egypt sent pillars of alabaster to uphold the ornate artwork on the roof. The Emperor of Russia shipped the precious malachite and lapis lazuli used in recreating the tabernacle and the two lateral altars of the transept. The Italian Government funded restoration of the principal facade, looking toward the Tiber River. King Fouad I of Egypt contributed columns and windows of fine alabaster, and the Vice-King of Egypt, Mohamed Ali, offered columns made of alabaster. Catholics from around the world contributed to help in rebuilding the sacred space.

Ultimately, most of the ancient basilica was recreated in later years, with only the apse and the triumphal arch remaining from the historical creation. The fifth century mosaics in the apse portray the Apocalypse of John, with the bust of Christ in the center flanked by 24 doctors of the church, and flying symbols representing each of the four Evangelists. Saints Peter and Paul stand at either side of the arch, with St. Paul pointing downward – probably to his tomb below.

 

Innovative Fire Safety Measures

At the time the Basilica of St. Paul Outside the Walls burned, there was unrest in the society; and several other churches had been vandalized, suffering intentional damage or destruction. Regardless of the cause of the basilica fire – whether intentionally set, or the fault of a careless worker – Pope Gregory XVI wanted to be certain that it could never happen again. Under his direction, the restored basilica was constructed with the world’s first automatic fire detection and alarm system. Pope Gregory invited Luigi Poletti, a renowned Italian architect and engineer, to provide the new roof and the entire basilica with a fire protection system. Poletti in turn asked Fr. Angelo Secchi, an Italian astronomer and directory of the Observatory at the Pontifical Gregorian University, to develop a new plan.

Fr. Secchi’s new system was developed in cooperation with the Luswerghs, a family of engineers who worked to craft scientific apparatus in Rome. The comprehensive new fire control system included water reservoirs, pumps, lightning rods, thermometers, and a thermoelectric fire warning device powered by two electric batteries. There was also a telegraphic system which connected the basilica with a control room in central Rome.

The innovative fire protection system was never needed. There was never a fire in the basilica in the ensuing years; and by the beginning of the 19th century, the system was deemed obsolete and was replaced by more contemporary fire control equipment.

In November 2017, the Italian Fire Services held an international conference in Rome at which scientists discussed Fr. Secchi’s system for protecting the basilica.