Notre Dame Cathedral in Paris will host its first Mass on June 15 two months after a fire engulfed the historic, 856-year-old church, causing widespread external damage and its spire to collapse.

A small Mass will be celebrated by Paris Archbishop Michel Aupetit. According to the Archdiocese of Paris, the Mass will be held “on a very small scale late Saturday,” in a “side chapel with a restricted number of people” — at least 20 religious.  

According to French media, the undamaged chapel is where Jesus Christ’s original Crown of Thorns is usually kept.

The June 15 date was chosen because it coincides with the anniversary of the consecration of the cathedral altar, celebrated annually June 16.

The Mass will be broadcast live on French TV, “so that Christians from all over France can participate,” the archdiocese added. It is also awaiting an official response over whether it can re-open the parvis to the public, hoping to celebrate evening prayers in that open space in front of the cathedral building.

No official cause of the April 15 fire has been determined, though investigators have speculated it could have been electrical or cigarette-related.

The landmark’s original 19th-century pipe organ also survived the fire, with some minor water damage.

French President Emmanuel Macron has promised to restore the cathedral to its original state, in the next five years before the city hosts the summer Olympics in 2024. Business organizations philanthropists have pledged millions towards reconstruction.