If any Muslim who suffers some calamity says -

إِنَّا لِلَّهِ وَإِنَّا إِلَيْهِ رَاجِعُوْنَ اَللَّهُمَّ أْجُرْنِيْ فِي مُصِيْبَتِيْ وَأَخْلِفْ لِي خَيْرًا مِّنْهَا

Innaa lillaahi wa 'innaa 'ilayhi raaji'oon, Allaahumma'-jurni fee museebatee wa 'akhliflee khayran minhaa

We are from Allah and unto Him we return. O Allah take me out of my plight and bring to me after it something better. Allah will give him something better than it in exchange.

Reference: Muslim: 918