Mosul Chow Hall Bombed?

I'm hearing now that the attack on the chow hall in Mosul may have been a suicide bomber. That is not so surprising. For one, see my previous post. For another, it is not easy to hit a specific target by indirect fire, and it is particularly difficult in daylight, with makeshift artillery, when Americans are actively looking to prevent such attacks. If several shots are fired and adjusted in, it's possible, but for one accurate shot to hit the target, unlikely. So, suicide bomber seems the likely cause.