Network is gone, but don't you fret.

Here's an image, Service Worker has stored it's caching pocket.

Offline chicken is offline.

And here's what that little devil has fetched while you were browsing my site:

Now here's is another image; but this is not covered by the service worker. So either you'll see it (if it landed in the regular browser cache while you've been online), or you'll get a SVG-placeholder (shamelessly stole that from Jeremy's gist).

Image not covered by service-worker.