I think it's already hot from being on the ground without air conditioning so the pressure inside the can is already elevated. And then when the plane gets to

I think it's already hot from being on the ground without air conditioning so the pressure inside the can is already elevated. And then when the plane gets to cruising altitude, the cabin is at the equivalent of 8000 ft (~2350m) so the pressure differential between the inside of the can causes it to burst.