Can't load the web page

I tried to buy things online from oldnavy.com but all the sudden the page disappeared and can't load the page at all. When I try to load it, the word above the page said loading oldnavy.com and keep blinking like that. I tried gap.com and bananrepublic.com also but I got the same problem. But another web sites are fine. I tried to do this for awhile and really upset with this. Anybody can help me what's wrong with my safari?