Pitts, J. Brian. "Why the Big Bang Singularity Does Not Help the Kalam Cosmological Argument for Theism", British Journal for the Philosophy of Science 59 (2008), pp. 675-708. Here is the link.
Perhaps it's worth noting that unlike William Lane Craig, James Brian Pitts actually has a PhD in physics.
UPDATE: Commenter "Pastor Tom" has kindly pointed out that Craig has offered a reply to Pitts. Here is the link. I leave it to the reader to decide whether Craig's reply is adequate.