At least nine people are unaccounted for hours after the blast , city officials say . A woman tells CNN her aunt was among the victims killed . `` That mitigation is in process and will likely take several hours . '' A sinkhole in front of the buildings complicates search efforts . Comment:
At least nine people are unaccounted for hours after the blast , city officials say . A woman tells CNN her aunt was among the victims killed . A sinkhole in front of the buildings complicates search efforts . Comment: