March 19 is the Feast of Saint Joseph, most chaste spouse of the Blessed Mother Mary and the foster father of Jesus.

Saint Joseph is traditionally known as a “carpenter”, “craftsman”, and “handyman" of the neighborhood.

 Many devotees invoked St. Joseph's powerful intercession for necessities and material blessings.

Among those who prayed for his help were the Sisters of Loretto who were able to start the construction of Chapel of Loretto or the Chapel of Our Lady of Light in Santa Fe, New Mexico in 1873 and were tasked to maintain it. The French Gothic-style chapel was inspired after the Sainte-Chapelle in Paris.

The nuns' nine-day novena prayer to Joseph the Carpenter was behind the mysterious construction of the six-meter-high, spiral staircase inside the Chapel of Loretto.

The Sisters of Loretto were caught in a bind after the builders failed to consider setting up a staircase that would connect the chapel’s ground floor to the choir loft 20-feet above.

At that time, the building’s renowned French architect, Antonio Mouly, passed away before access to the choir loft was constructed.

"When the nuns insisted on building a staircase, the builders told them it would be impossible, and that building a normal, regular ladder would take too much room. Finally, they advised the nuns to demolish the choir. Instead, the nuns decided to pray a novena to St. Joseph, patron saint of carpenters, asking for a solution,” said Aleteia.org, an online Catholic news and information website which has “inspired” over 20 million people worldwide.

Citing the testimonies that have passed from generation to generation since the mid-19th century, the Aleteia.org said on the ninth and final day of novena prayer, a man showed up and volunteered himself to build a stairway provided that he be granted total privacy.

"The stranger locked himself in the chapel for three months with a saw, a square and a few other simple tools, and disappeared as soon as the work was finished, without ever having asked for any payment for his services,” it said.

Built without any nails or glue, and lacks any kind of central support, the staircase takes two full turns over its axis until it reaches the choir. it said.

"The construction itself is said to be impossible,” the Aleteia.org said.

Quoting some accounts, it said "the original staircase was not attached to any wall until 1887, 10 years later, when the railing was added, and the outer spiral was attached to a nearby pillar.”

Until now, the identity of the mysterious carpenter has yet to be identified and no delivery report has been traced  that might help decipher where the wood came from.

The staircase is known to be made of spruce wood, which is not native to the American Southwest.

"During those three months, no one saw anyone entering or leaving the chapel,” the Aleteia.org said.

"As the carpenter left before the Mother Superior could pay him, the Sisters of Loretto offered a reward to anyone who could his make identity known, but no one ever showed up. So, yes: since then, the crafting of the staircase has been attributed to St. Joseph himself!,” it said.

This legend inspired the production of a movie “The Staircase” in 1998, starring Barbara Hershey and William Petersen.