Usually, once it's deleted it's gone.
Do you mean by "from the website" your local web (on your PC), or the remote
(host server) site? The host may well have back ups of the site; they can
retrieve/restore the file I expect, but you'd have to ask them.
If deleted it from the remote host, then republish the page from the local
web.
If deleted from your local copy then publish the page down from the remote
host.
If you work "live on the server" with no local copy (very bad idea for this
very reason - or if the server crashes) - change your work habit to working
on a local copy, where you can easily create backups to external hard drive,
DVD/CD or flash drives.
