Arjuna arrives in Dwaraka.Kaliyuga begins. Mahabharata 205

Arjuna hears about the destruction of yadavas and arrives in Dwaraka, which has the appearance of a dry lifeless river. Seeing Arjuna, Satyabhama, Rukmini and the yadava women begin to cry. He manages to calm them a little and goes to Vasudeva and falls at his feet. Vasudeva remembers his children and cries, "Arjuna! Heroes who had killed hundreds of demons and kings are gone! I am still alive. My jeeva is too strong! Your favourite people, the ones you loved and liked, Satyaki and Pradyumna, became the main cause of vrishni's destruction. Why blame others, Krishna himself was indifferent. While he resurrected the child killed by Ashwatthama's astra, could he not save his own family? He did not want it. After his children, grandchildren, friends and relatives all died, he came to me and said, 'It is the end of our clan! Arjuna will come here, tell him about it. He and I are the same, do as he tells you. He will perform the last ceremonies for the dead. After he leaves this city will be submerged under the sea. I will go to the forest and will be with Balarama in a sacred place and wait for this era to take its course'. He then asked me to take care of the children and went away. In this worry, I am unable to anything,  neither can I  eat food nor drink water. I am neither alive nor am I dead. Fortunately you have come, do as Krishna wants. Take care of the kingdom, the women and children and the wealth. I will leave this world."

Next morning, Vasudeva,  leaves his body while meditating. His four wives accompany him in his death. Arjuna performs ceremonies for them and the dead yadavas.As the city would soon go under the sea, he tells the people to be prepared to leave with their belongings in about a weeks time. The whole town leaves, using all means of transport; elephants, horses and mules. As there are no more leaders left, the people themselves become guards. Arjuna takes lead and guides them out of the town. As they leave, the sea turns towards the city. And wherever they halt, the sea soon reaches the spot and they are forced to move again. They believe that this extraordinary situation is the will of god and keep moving. Thus they cross hills, rivers and forests and finally Arjuna brings them to Panchanada, a place which is full of cows and grains. 

The group consists  mostly of women and  with only Arjuna as their protector. The rest of the guards are incapable of protecting the women. The bandits notice this and thousands of them attack. Arjuna comes forward and threatens them, they do not care. Arjuna picks up his bow, gandiva, and finds it difficult to string the bow. He finally manages to get ready but forgets the astras. He feels terribly ashamed at his weak body and his forgetfulness. The vrishni soldiers who are riding the elephants and horses are also unable to drive away the robbers.  The greedy men grab whatever the women possess and some of them even drag the women away with them. Arjuna kills hundreds of them and suddenly he sees that his quill is empty. The quill which never emptied during the Bharata war has nothing in it now. Arjuna decides that it is gods will and manages to hit as many bandits as he can using the tip of his bow. He is very unhappy and he finally gives up on those who were abducted and brings those who remained to Kurukhestra.

A little while later, Arjuna with the permission of Yudhisthira, installs the young men who would help the perpetuate the clans. Kruthavarma's son in Mrutthikavatha, Ashwapathi in khanadava forest and Satyaki's son at the banks of saraswati. Krisha's grandson is installed in Indraprasta.

Akrura's wives go to do penance in the forest. Rukmini and Gandharakumari Shaibye, Hymavati and Jambaavati immolate themselves. Satyabhama and other wives of krishna also go to the forest to do penance. 

Without  Krishna Arjuna is helpless.

Friend Chandramouli labelled it as the Beginning of Kali Yuga. I have many questions on this, but it can wait. 

But here are some explanations about Kali Yuga:
Hindus believe that human civilization degenerates spiritually during the Kali Yuga, which is referred to as the Dark Age because in it people are as far away as possible from God.
Kali Yuga is associated with the apocalyptic demon Kali, not to be confused with the goddess Kālī (read as Kaalee) (these are unrelated words in the Sanskrit language). The "Kali" of Kali Yuga means "strife, discord, quarrel, or contention."

Attributes of Kali Yuga
A discourse by Markandeya in the Mahabharata identifies some of the attributes of Kali Yuga:

In relation to rulers:

• Rulers will become unreasonable: they will levy taxes unfairly.
• Rulers will no longer see it as their duty to promote spirituality, or to protect their subjects: they will become a danger to the world.
• People will start migrating, seeking countries where wheat and barley form the staple food source.
• "At the end of Kali-yuga, when there exist no topics on the subject of God, even at the residences of so-called saints and respectable gentlemen of the three higher varnas [guna or temperament] and when nothing is known of the techniques of sacrifice, even by word, at that time the Lord will appear as the supreme chastiser." (Srimad-Bhagavatam (2.7

In human relationships:

• Avarice and wrath will be common. Humans will openly display animosity towards each other. Ignorance of dharma will occur.
• People will have thoughts of murder with no justification and will see nothing wrong in that.
• Lust will be viewed as socially acceptable and sexual intercourse will be seen as the central requirement of life.
• Sin will increase exponentially, whilst virtue will fade and cease to flourish.
• People will take vows and break them soon after.
• People will become addicted to intoxicating drinks and drugs.
• Gurus will no longer be respected and their students will attempt to injure them. Their teachings will be insulted, and followers of Kama will wrest control of the mind from all human beings.The maximum lifespan of a human in this age is 90-100 years.
• Brahmans will not be learned or honored, Kshatriya's will not be brave, Vaishyas will not be just in their dealings