$ juju destroy-model --force charm-testing-cassandra-bionic-137
WARNING! This command will destroy the "charm-testing-cassandra-bionic-137" model.
This includes all machines, applications, data and other resources.
Continue [y/N]? y
Destroying model
Waiting for model to be removed, 3 machine(s), 2 application(s).....
Waiting for model to be removed, 3 machine(s).....
Waiting for model to be removed, 2 machine(s).....
Waiting for model to be removed, 1 machine(s).....
Waiting for model to be removed....
Model destroyed.
It seems to work okay with --force, fwiw:
$ juju destroy-model --force charm-testing- cassandra- bionic- 137 testing- cassandra- bionic- 137" model.
WARNING! This command will destroy the "charm-
This includes all machines, applications, data and other resources.
Continue [y/N]? y
Destroying model
Waiting for model to be removed, 3 machine(s), 2 application(s).....
Waiting for model to be removed, 3 machine(s).....
Waiting for model to be removed, 2 machine(s).....
Waiting for model to be removed, 1 machine(s).....
Waiting for model to be removed....
Model destroyed.