The explosion could be heard from St. Peter’s Square to the Piazza di Spagna to the Janiculum Hill. Those on the upper floors of buildings were treated to the remarkable sight of a red-and-orange fireball rising over the northern end of the Villa Borghese, followed quickly by a pitch-black mushroom cloud of smoke. Windows a mile from the blast point were shattered by the thunderclap of the shock wave, including the stained-glass windows in a nearby church. Plane trees were stripped of their leaves. Birds died in mid-flight. Geologists at a seismic monitoring station first feared that Rome had been shaken by a moderate earthquake.

None of the Italian security men survived the initial blast. Nor did any of the fourteen visitors waiting to be admitted to the mission, or the embassy personnel who happened to be working in offices closest to the spot where the truck exploded.

Ultimately, though, it was the second vehicle that inflicted the most loss of life. The Vatican courier, who had been knocked to the ground by the force of the blast, saw the car turn into the cul-de-sac at high speed. Because it was a Lancia sedan, and because it was carrying four men and traveling at a high rate of speed, he assumed it was a police vehicle responding to the bombing. The priest got to his feet and started toward the scene through the dense black smoke, hoping to be of assistance to the wounded and the dead alike. Instead he saw a scene from a nightmare. The doors of the Lancia opened simultaneously, and the four men he assumed to be police officers began firing into the compound. Survivors who staggered from the burning wreckage of the embassy were mercilessly cut down.

The four gunmen ceased firing at precisely the same time, then clambered back into the Lancia. As they sped away from the burning compound, one of the terrorists aimed his automatic weapon at the Jesuit. The priest made the sign of the cross and prepared himself to die. The terrorist just smiled and disappeared behind a curtain of smoke.