On the day the Holy Father resigned.

The Italian caption reads:
L'immagine del giorno è di Alessandro Di Meo, fotografo dell'agenzia Ansa. Il fotoreporter è riuscito a catturare la caduta di un fulmine sulla cupola di San Pietro proprio nel giorno dell'annuncio delle dimissioni di papa Benedetto XVI

Loggot's (from Fisheater's) translation:
Today's picture is by Alessandro Di Meo, photographer of the Ansa agency. The photojournalist was able to capture a lightning bolt falling on the cupola of Saint Peter's, on the very day of pope Benedict XVI's resignation announcement.

Holy father, I love you. You were a great pope. I wish you had died with your boots on. You were in my prayers before the Blessed Sacrament today. We will keep you in our intentions.