Why did Cinna die when Katniss went in the tube to go in the Games?

cinna died because he had unabashed involvement with the rebellion and his relationship with Katniss.

Explanation:

hope this helps babe

The main reason that he died is because he turned Katniss dress into a mocking jay. This was seen as a rebellious act and a defiant one. This was not liked by Snow so he had cinna killed. Cinna knew he was going to die because he said "I put my emotions in my work so I dont hurt anyone but myself"which ultimately led to his death.

Explanation:

recent news about two years ago indicates that a polish forestry student by chance unearthed at a depth of about 40cm (16 inches), during digging in a damp polish forest he found a 13-page manuscript into a thermos flask.

greek jew marcel nadjari was a aischwitz slave who witnessed how the nazi's built big death chambers and crematoriums and told how he was forced to escort fellow jews to the gas chambers. he accounts on this manuscript how the nazi's disguised this chambers to look like showers. also, he describes this place as a process of extermination from the chambers to the trains arriving to take the bodies.