He will be responsible for the administration of the Vatican and the worldwide Roman Catholic Church during this period, called the interregnum, which will last until the College of Cardinals chooses a new pope.
Somalo's first duty is to verify the death of the pope. According to tradition, the camerlengo does this by calling Pope John Paul's baptismal name, Karol, three times without answer. He does this while tapping the pope's head with a silver hammer, although this symbolic gesture may be substituted by simply placing a veil over the pope's face.
Once the camerlengo is satisfied, tradition holds that he must make a pronouncement, in Latin, to those gathered around the deathbed:
Vere, Ioannes Paulus II mortus est -- "Truly, John Paul II is dead."
He must do this in the presence of two officials: the master of papal liturgical celebrations and the secretary-cardinal, Camillo Ruini, who then conveys the news to the waiting people of Rome, probably through a television announcement.
The camerlengo then authorizes the death certificate and seals the papal apartment, posting a guard outside.
He takes possession of the pope's Fisherman's ring and seal, which will be ceremoniously smashed with a hammer at the first gathering of the arriving cardinals as a symbol of the end of the papacy (although the original purpose was to prevent forgery or other misuse).
A new Fisherman's ring, with the pope's name around the circumference and an image of St. Peter casting his fishing net in the center, will be struck for the next pope.
Bells toll in St. Peter's Square and throughout Rome. The doors to the papal palace are bound with heavy chains, a sign that life has come to a halt. The white-and-gold Vatican flags are lowered to half-staff.
And the Vatican begins minting coins and striking medals commemorating the Sede Vacante, the period in which there is no pope, the sale of which helps defray the cost of the funeral.
Vatican officials officially notify heads of state around the world of the pope's death and summon the College of Cardinals to Rome by telegram. Customarily, it is a terse message. The telegram that cardinals received after the death of Pope Paul VI simply stated: "Pope is dead. Come at once."
The pope's confessors dress him in his funeral garments: a white cassock, a scarlet chasuble (a long, sleeveless liturgical vestment) and red silk shoes, and then take the first watch at vigil.
The pope then lies in state for three days, first in the Clementine Hall of the Apostolic Palace, and then is taken in solemn procession to St. Peter's Basilica, where the faithful file past his body as Vatican guards urge them on with cries of "Avanti! "
Traditionally, the funeral takes place on the fourth day after a pope's death.
It was held inside St. Peter's until Pope Paul VI decreed that his service be held in St. Peter's Square so more people could witness it. The funeral of John Paul I followed suit, despite a chilly downpour.
The symbolism is simple. The pope lies in a cypress coffin. A large white Easter candle recalling the resurrection of Jesus stands at one end. On top lies a Book of Gospels.
After the ceremony, which typically lasts two hours, two lines of pallbearers take the coffin to the grotto of St. Peter's for a private burial service with a few cardinals and the pope's family. The cypress coffin is placed in a lead coffin and then an oaken box.
As the pope is placed in his tomb, a cardinal reads an elegy, written in Latin, recounting the accomplishments of his papacy.