Tropical Zone Gardening: Young Papaya Trees dying , 3 by Malki22

Malki22 wrote:
Hello,

I have about 12 papaya young trees, around 1 year old, started them from seeds and moved them to large containers with a well-drainage soil mixture. during the summer period i had them out in the sun and they were growing fast, but as winter came I had t move them into the house, where they have a good amount of light from the windows and heating.

but now they are dying one by one, first the leaves start to curl and face downward, but there still green and arent dry, then the bark start to lean down and eventually fall from the point where the bark meets the soil.

I have attached photos

Please help, whats causing this, is it a disease, rot, or the cold weather?