᯽The sentence which broke everyone᯽

Lord Rama sentenced his beloved brother Lakshman to death.
It is mentioned in the Valmiki Ramayana that Shri Rama sentenced his beloved younger brother Lakshman to death, but do you know why Lord Rama sentenced Lakshman to death?
This incident occurs after Sri Ram returns to Ayodhya after Lanka's victory and is crowned king of Ayodhya.
Yama Devta came to see Sri Rama one day to discuss an important matter.
Before beginning the conversation he asked Lord Rama to promise him that no one would interrupt it until it was finished or else he would have to give the death penalty to that person.
Ram designated Laxman as the gatekeeper to ensure that no one interrupted their conversation. 
Durvasa rishi arrived a few moments later and asked Lakshmana to inform Ram of his arrival which Lakshmana humbly denied.
Rishi Durvasa became enraged and declared that he would curse Ayodhya as a whole. Laxman decided to sacrifice himself to save Ayodhya.
He went inside to notify Lord Ram of his arrival.
Shri Rama was perplexed at this point because he was required to execute Lakshman in accordance with his promise.
In this situation, Shri Ram remembered his Guru Vasishta and asked him to show him the other way.
Guru Vasishta said leaving Lakshman is the same as giving him the death penalty. After hearing this, Lakshman stated that he cannot stay away from his brother for the rest of his life.
Laxman chose to accept death by obeying his brother's command.
Lakshman then went into Hal samadhi.