What do Muslims say in the face of tragedy?

"Be sure We shall test you with something of fear and hunger, some loss in goods or lives or the fruits (of your toil), but give glad tidings to those who patiently persevere,

Who say, when afflicted with calamity: “innaa lillaahi wa innaa ilayhir raaji-oon -- to Allah we belong,and to Him is our return"

They are those on whom (descend) blessings from Allah, and Mercy, and they are the ones that receive guidance.

[Quran 2:155-157]