NWOBHM legends DIAMOND HEAD were forced to cancel their show tonight (Tuesday, July 3) at the O2 Academy in Islington, London, England after the band's drummer, Karl Wilcox, was admitted to hospital with a suspected blood clot. The group issued an update on his condition later in the day, stating, "Karl has had hospital treatment today and should be fit again by tomorrow morning. We hope to go ahead with the York show tomorrow, but please check with the venue before setting out. The show on Thursday 5th July at Wolverhampton, and the remainder of the tour will go ahead as planned."For the first time in its 35-year history, DIAMOND HEAD made its way stateside for a U.S. tour in the summer of 2011. DIAMOND HEAD's only previous U.S. appearance was at the Metal Meltdown IV festival in Asbury Park, New Jersey in 2002 for a sold-out show with fellow British stalwarts SAXON and WITCHFYNDE. Now, for the first time ever, DIAMOND HEAD's U.S. fans got the opportunity to see the band perform live. The tour kicked off in Seattle on August 15 and concluded in New York City on September 1. DIAMOND HEAD's first-ever appearance with the "Big Four" (METALLICA, SLAYER, ANTHRAX and MEGADETH), the artists on whom they had a major influence, at the Sonisphere festivals in the U.K. and France, was followed by their first performances in Canada, playing with MOTÖRHEAD, and MEGADETH at the Heavy TO festival in Toronto, along with an appearance with GIRLSCHOOL, MOTÖRHEAD and KISS, at the Heavy MTL festival in Montreal.