Call does not end when all participants leave

Observed behavior:

When using calls in a channel or direct message you may occasionally see the call continue with zero participants.  Our engineering team is currently investigating this issue and working to resolve it.

Solution:

You can utilize the command /call end to force a call to close.  To do this in a channel you will need admin access to the channel or team.  In a direct or group message any participant can run this command.