The Great Fire of Rome in 64 A. D. began in the Circus Maximus. It swept violently over the level spaces and climbed the hills. Women, old and young people fled from the flames. Some preferred to die because they had lost their possessions or loved ones. Nobody fought the flames, but some threw torches in, claiming that they had acted under orders.
Nero was at Antium, returning to the city only when his palace was threatened- although it was completely destroyed. He threw open the Field of Mars for the relief of the homeless, and brought in grain from surrounding towns at low prices. Some claimed that he had deliberately started the fire in order to build a new palace for himself.
By the sixth day the fire had been stamped out at the foot of the Esquiline Hill, but another broke out in the more open districts of the city, starting on Tigellinus' estate in the Esquiline district.
Of Rome's Fourteen districts, only four remained intact, and three were completely destroyed.
Read more about Early Christians and the Burning of Rome from Michael Streich