The Pandavas and Kauravas grew up in Hastinapura. The former were better with weapons and were also the favourites of the court. Duryodhana became jealous and began hatching a plan to get rid of the Pandavas. He took permission from Dhritarashtra to build a new palace at Varanavata. Most people didn’t realise that it was made of lac, but the Pandavas knew, though they didn’t reveal it. Duryodhana and his minister Purochana had the Pandavas shifted to the new palace and Duryodhana decided to burn the Pandavas there when he got the chance. Vidura informed the Pandavas about this through his messenger Khanaka. One night, as the Pandavas were sleeping, Purochana set fire to the palace. The Pandavas, however, escaped through a tunnel that had been built earlier. That night, a tribal woman with her five sons had also been sleeping in the palace. Since they were intoxicated they didn’t wake up until it was too late. Purochana also died accidentally in the fire. The crowd who gathered there assumed that the Pandavas and their mother had died. As per Mahabharata Adiparva Chapters 141-151, this happened a year after the Pandavas had stayed in the palace.