Keyboard interrupt does not work when using multiple gpus

During the training process using 2 GPUs, I tried to kill python using ctrl+C from terminal, but the terminal session became dead. When I logged on using another session, and tried to look at GPU usage by nvidia-smi, this command again caused dead session (other commands were fine). What might be the reason? If I want to kill the training, is it better to use kill command instead of ctrl + C?