If your SiteGround site is down, it may be due to them moving your site to a new server.
That would naturally cause a change in the IP address too.
When my clients called SiteGround support, they were all told that an email had been sent to warn them about the upcoming server change.
None of my clients received that email.
How to Fix Your Site
If you’re using Cloudflare, you will need to update that IP address in 2 places.
See the tutorial below for how to do that.
If you’re not using Cloudflare, check at your domain registrar, or any other CDN that you may be making use of the direct IP address to your site files at the host.
This book could save you hundreds of dollars and months of frustration. Get it free with your subscription to 
This book could save you hundreds of dollars and months of frustration.