Personally I think Selco’s own experience is a prime example of what will happen long term. Katrina shows us how fast LE will dissolve. There will be mixtures of localized authority until there is none, just as every novel and movie depicts. Early on in a national/global crisis government at every level will try to respond with LE/military personnel, but as the crisis deepens less and less resources will be available to respond.
If you use a pandemic as the cause of collapse no one will show up to do anything after a short time. Everyone will want to stay away from others and everything will need sanitizing. Now that the nurse in Spain was infected even though she used a high level of PPE and was in a contained environment, even people wearing hazmat suits will not want to expose themselves. Over 300 medical workers have been infected who were wearing PPE.