deadly explosion in cache chi. dominic cache chi. dominic is joining us live. reporter: jenna, here s what happened just over two hours ago, a suicide car bomber drove himself up to the headquarters of the criminal investigation department in the southern port city of karachi and blew himself up killing 12 people and as many be as 90 people injured. this happened very close to an area that includes the u.s. consulate and two big western hotels, the marriott and scherr tan, however, no indication that westerners have been injured in this particular blast. it left a crater 10 foot wide and is, apparently, one of the biggest blasts that we ve actually seen to hit pakistan in quite some time leveling much of the police building. as many as 40 people still believed to be beneath the rubble. we believe it could be militants who are trying to actually spring people from the police headquarters. the headquarters known for being a detention center, an interrogation center for the militants