A brief timeline (as per my understanding) 
1528: Babri Masjid was built under the rule of Babur by Mir Baqi. The masjid was constructed on top of a small hill, Ramkot. Till about 1940s, the masjid was also known as Masjid-i-janmsthan. 

1853: first riot to have occurred between Hindus and Muslims on Babri Masjid and lord Ram’s birth place. 
1885: the case was taken to Faizabad court that gave the verdict since the mosque has been built and is present for more than 356 years already, it would not be appropriate to question the existence of the present structure. 
1949: between the nights of Dec 21-22, an idol of lord Ram appeared inside the structure (which was closed and no namaz used to be there at that time)  
1986: after the Shahbano case and the miserable buckling act of the Congress for the muslim clerics, the then PM Rajiv Gandhi sought this issue as a come back in the minds and hearts of the Hindus. The Faizabad judge gave orders to open the locks of the structure, within 2 hours the government agreed and the entire incident was telecasted by Doordarshan. 
1989: VHP announced that after 9 months, the work on the construction of Ram mandir would start. 
October 1989: Already 706 riots had taken place in the span of little over a year and more than 1000 had died. 
3rd November 1989: Rajiv Gandhi gave a speech in Faizabad. The important part being, both the matter of the speech and the location of the speech to be delivered were changed at the last moment. The speech talks about Rajiv Gandhi himself bringing back ramrajya and being a proud Hindu. Both the aspects were not present in the original speech as per Manishankar Iyer. 
30th October 1990: it was announced that Ram mandir would be constructed. 
25th Dec 1990: the 10,000km rath yatra of kar sevaks started from Somnath. The destination was Ayodhya. 
1991: elections took place, Rajiv Gandhi was assassinated and congress came into power. Narsimha Rao was the PM
June 1991: Kalyan Singh became the CM of UP. In the next 4 weeks of becoming the CM, he visited Ayodhya and declared that the mandir would be constructed there itself. 

After 15 days, he gave 2.77 acres of adjacent land to a trust made for the construction of the mandir for INR 1. 
31st October 1991: some kar sevaks climbed the dome and waved saffron flag. Kalyan Singh promised that he would take care of the security of the structure. 
1992: talks started between VHP leaders and Babri Masjid Action Committee to resolve the issue outside the court. It seemed that maybe some peaceful solution is a possibility. 
30th October 1992: VHP dismissed the talks, announced that the attempt failed and gave the date of 6th Dec 1992 for restarting the kar seva. 
8th November 1992: again a meeting was held between the action committee and VHP members. The head of the sunni Waqf Board opposed the VHP announcement. The talks had officially failed. 
Sensing the rising communal tensions, the then Home Secretary , Godbole, suggested to the PM that in situations like this, the center can intervene by sending security forces by land, air and rails to Ayodhya and make sure that peace is not disturbed. PM was informed that all arrangements can be made by 23rd Nov and he can make the announcement of president’s rule on 24th November 1992. 
23rd November 1992: the then PM still wanted to resolve the issue with talks and was not keen on taking a major step. A meeting with the BJP leaders was announced which was in turn boycotted by the BJP leaders themselves. 
Neither the state not the central government urged the Allahbad high court to speed the process and give the verdict soon keeping in mind the rising tensions. 
5th Dec 1992: AB Vajpayee and Advani gave speeches in Lucknow. The infamous speech of Vajpayee stating “zameen ko samtal karna padega” was made here. 
6th Dec 1992: 2 lac karsevaks gathered around the structure. At about 12 o clock, one of them started climbing one of the domes. The rest followed. One by one, all three domes were destroyed. People were celebrating, sweets distributed and gulaal used to show the happiness. Uma Bharti in her ecstasy climbed Murli Manohar Joshi’s back. 

After the incident, to avoid any blame, the then PM gave the matters to be investigated to a one man commission called the Liberhan commission and asked him to give the report in 3 months. 

The report was given after 17 years and INR80 million later. 
2009: the report of the Liberhan Commission was leaked to the media before it could be read in the House of Parliament. Caused havoc in parliament. The report accused Vajpayee and Advani as being the ideological architects of the incident with RSS being the main culprit. The report also talks about the then CM Kalyan Singh’s government posting out the bureaucrats who could in any way hinder the plans for 6th Dec 1992. 
2017: the Supreme Court restores the criminal case against senior BJP leaders. Directs to give a ruling in 2 year’s time. 

The inability of the center to intervene , the silence of the Congress for their political gains, the inability of the whole system lead to what happened on 6th Dec 1992. 
People failed as humans, politicians failed as leaders and the country failed as a system. 
The speeches of Kalyan Singh, Advani, Vajpayee are so communal and so instigating that imagining their effect on people is reason enough to give one goosebumps. 
To understand why on every 6th December people shout on television channels and why so many of them are angry, it’s important to understand the significance of December 6th, 1992.