While we are still working to be able to send SMS notifications for individual server issues, we have added a status page that can send SMS messages if there are any wider issues.
Please see and sign up for Notifications at:
Liquid Web and MWP:
These include email, SMS, and RSS notification options.
An error occurred while saving the commentKarina commented
There are other sites (paid and free: https://hostingfacts.com/website-monitoring-services/) that will monitor uptime and send SMS if something goes down, but I agree that it would be great if Liquidweb themselves provided the service.