Calamity (noun)

1. A state of great trouble or misfortune caused by natural or human actions, such as an accident, a war, a flood or an earthquake.
2. A state of great trouble or distress.
3. A disastrous event.

Origin:

From latin calamitātem, from calāmitās, meaning "misfortune, disaster".

Examples:

1. The flood was a calamity that destroyed many homes.
2. The war was a calamity that caused the loss of many lives.
3. The earthquake was a calamity that caused widespread damage.
4. The financial crisis was a calamity that caused many people to lose their savings.
5. The accident was a calamity that caused many injuries.