ID:278032
 
If the world gets disconnected, like if the host lost connection to the internet, does the world.Del() proc get called?
No. However, all external clients will of course be disconnected.

If you wish to verify if the host has a connection to the internet, you could try using world.Export() to ping a server or retrieve a file off of a HTTP source.

world.Export("http://www.microsoft.com") for example. If this returns null or otherwise does not have a "CONTENT" entry (world.Export() returns an associative list) then the host likely does not have an connection to the internet.

Note that it is possible to determine if the host has a connection as well by checking world.internet_address. This variable will be null if the game was unable to contact the BYOND Hub.
In response to Android Data
Android Data wrote:
Note that it is possible to determine if the host has a connection as well by checking world.internet_address. This variable will be null if the game was unable to contact the BYOND Hub.

Just a note: This isn't the same as whether the game is online.