No one killed him. It was God’s wish. On hearing that the slayer of his father is coming again for a war, he died out of fear.

I have not come for war. I have come as the protector of the sacrificial horse.

My elder brother is conducting a Yaga, and as per his directive I am following this horse.

Please tell me, who killed your son. I shall take revenge on him.

Don’t do that. Have you forgotten all my earlier advices (Bhagavath Geetha).

Be courageous, you are a warrior, a Kshatriya.

O! Brother of Bheema, those who killed your valiant son treacherously, they too should meet their end soon.

O! Son of Nanda! How can I return home without my son? How shall I face your sister (and my wife) Subhadra now that her son is dead?

For what, this war ? For what, the kingdom ? Death is better than this woe.

Our loss may be irreparable, but such wailing does not become a warrior like you

You have to avenge his death in war, and that victory shall earn you glroy

My beloved Abhimanyu ! My dear son! Why did you take such a risk?

O! Such a great tragedy! You are the bud that we have nurtured so lovingly. And today your neck is shattered by the greed of our enemies.

Dear Krishna ! Are you not aware of this tragic end to our dear Abhimanyu.

Sloka:
Efforts by Lord Sri Krishna to avert the war failed.. War was imminent and both sides were preparing for it. A messenger from King Duryodhana came to King Jayadratha’s court to request him to participate in the war. 
 

O! Respected King of Sindhu, I am bowing before thee, who are the abode of valour and strength. I am a messenger sent by your brother-in-law, King Duryodhana.

The cunning Yadava (Krishna) came as an envoy from the son of Kunthi (Yudhishtira).

He requested that Duryidhana hand over half of his kingdom as a condition for peace.

As the sea rolls out a beautiful carpet of waves to welcome her

Blushing with love, she nears the Moon

Jasmine flowers with blossoming smiles welcomes her

And the gentle breeze fans her

The birds nesting with sweet songs

Act as a good omen for her

Darling, you were created (by Brahma) with all lovely things in the world like beautiful flowers, fragrant sandal paste mixed with the moon rays (according to mythology moon-light contains the essence of 'Amurth' - nectar).

Darling, the swans are bewitched by your exquisite incomparable gait and they try to imitage you.

The beautiful autumn night arrives in its chariot.

Wearing a beautiful necklace of stars

Sloka:

In the lovely evening as parrots and cuckoos sang sweetly, the beautiful Queen Dussala was sitting in the garden in grief.  Her husband, Jayadratha, the valorous king appeared and told her thus in a sweet, romantic mood;

Please come near, my dear, oh! one with honeyed lips.

Dear (you are the) embodiment all fine qualities, why are you annoyed?

Your face, always like the bright morning sky.

Now for what reason, is it disturbed and cloudy? 

This is the (evening) time to enjoy in the majestic garden with sweet love talk.