I was trying to stop and rm a container but it the command would not do anything:

CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                                          NAMES
13836a055eb0        6f2c24976acb        "/bin/sh -c 'cd /t..."   4 hours ago         Up 4 hours                                                         friendly_wescoff
7d547fa69006        817056550f95        "dumb-init node in..."   5 months ago        Up 2 weeks          0.0.0.0:95555->95555/tcp, 0.0.0.0:80->8989/tcp   hot_server_1

Turns out that the container 13836a055eb0 got stuck halfway through a build, unable to respond. The only solution I found was to reboot the EC2 instance.