Kamtza decided to have a party.

Kamtza wanted to invite Bar Kamtza.

Bar Kamtza was friends with Kamtza

An invitation was delivered to Bar Kamtza by mistake.

Bar Kamtza decided to go to the party.

When Kamtza saw Bar Kamtza at the party he told him to leave in front of every one.

Bar kamtza was embarrassed and begged to stay at the party.

Bar Kamtza even offered to pay for half the party if Kamtza let him stay.

Kamtza kicked out Bar Kamtza and no one stood up for him.

Bar Kamtza did not want to take revenge.

The Roman Emperor Nero sent a sheep back with Bar Kamtza but it was unacceptable for sacrifice because Bar Kamtza made a small cut on the animal.

When Emperor Nero heard the Jews didn't accept his gift he sent Titus to destroy Jerusalem and the Beit Hamikdash.

From this story we learn not to publicly embarrass anyone.

"Sinat Chinam" is baseless hatred.

Sinat Chinam is a reason given for the destruction of the second Beit Hamikdash.

"Baseless Hatred" means hating someone for no reason.

We remember this story every Tisha B'Av