From his bed he participated in Sunday Mass at 18:00. After communion, the pope suffered a massive heart attack, after which he continued to live for three hours. On 6 August 1978 at 21:41 Paul VI died in Castel Gandolfo. According to his will, he was buried in the grottos of the Vatican not in an ornate tomb, but in a grave in the ground. He is buried beneath the floor of Saint Peter's Basilica with other popes. In his will, he requested to be buried in the "true earth" and therefore, he does not have an ornate sarcophagus but an in-ground grave.

How long did Paul VI live for after experiencing a massive heart attack in 1978?