See below for GEO-TV's investigative report in Urdu on the security failures before and on the day of Ashura in Karachi. My comments can be seen here: "Six Talking Points About the Ashura Blast in Karachi" and "Muharram Blasts in Karachi: Why The Government is Implicated". Further, "On Militant Extremists in Pakistan and their Supporters."
See a similar investigative report by Dunya News that was released soon after the Ashura blast (December 28, 2010). It was very timely and insightful.