Safari redirecting to "Alert" page and not functioning.
While I was doing research for work (I teach social studies), I clicked on a link to view a worksheet another teacher had posted online. The link redirected me to a new page www.apple-alert-online.com/popup/ and the popup window says "Suspicious Activity - Major Security Issue" and to call apple support at 800-656-8559. I cannot get off this page, click out of the box, or do anything in safari, every button is gray and cant be clicked. I have quit safari and re-opened and it opened to the same page. Shut down and restarted my computer and it opened to the same page. HELP PLEASE!
MacBook Pro (13-inch Late 2011), OS X Mavericks (10.9.5)