LON­DON-Twit­ter blamed sys­tems fail­ures, not a crush of traf­fic around the Olympic games, for an out­age yes­ter­day that saw peo­ple around the world ex­pe­ri­ence prob­lems ac­cess­ing the mi­cro blog­ging site for more than an hour. The San Fran­cis­co-based com­pa­ny said the out­age was caused by a "note­wor­thy" dou­ble fail­ure in its da­ta cen­tres. When one sys­tem fails, a par­al­lel one is meant to take over, but two sys­tems co­in­ci­den­tal­ly stopped work­ing at around the same time, Twit­ter said. "I wish I could say that to­day's out­age could be ex­plained by the Olympics or even a cas­cad­ing bug," Mazen Rawashdeh, VP of en­gi­neer­ing, said in a state­ment apol­o­gis­ing to users. He apol­o­gised for giv­ing its users "zilch" in­stead of the ser­vice, say­ing the com­pa­ny is "in­vest­ing ag­gres­sive­ly" in its sys­tems to avoid a re­peat sit­u­a­tion. Vis­i­tors to the site on yes­ter­day were greet­ed with a half-formed mes­sage say­ing that "Twit­ter is cur­rent­ly down." The fields where a rea­son for the out­age and a dead­line for restor­ing ser­vice were ap­par­ent­ly meant to go were filled with com­put­er code. (AP)