It was morning rush hour. What’s believed to have been a massive truck bomb went off in the Afghan capital’s busy diplomatic district, leaving at least 90 people dead and 400 injured. The majority of the casualties are thought to be civilians. It’s not clear what the target was or who’s behind the attack — neither the Taliban nor ISIS, both of which have launched previous attacks, have taken responsibility. Meanwhile, ambulances and relatives rushed to the blast site, and officials warn that the death toll is likely to rise.