The Daily News has figured out via a source why the cost of Frank Gehry’s Atlantic Yards arena shot up to $950 million: the cost of making the glass bulletproof. (We would have thought bomb proof, but whatever.) Here’s some of the lowdown:

The stratospheric cost of protecting the Atlantic Yards from terrorist attacks could be the death knell for architect Frank Gehry’s flashy NBA basketball arena, the Daily News has learned. The bulletproof glass facade proposed for the glitzy arena will cost a mind-blowing $625 per square foot, a source familiar with the designs told The News.

“I think the owners clearly didn’t have their financing tied down for this project, and that’s going to be the biggest hurdle,” said the source, who spoke on condition of anonymity about the sky-high prices associated with securing the 850,000-square-foot arena against terrorism. “With the security concerns at the arena, there’s not much you can do to make it that much cheaper,” added the source…Sources close to the project said the cost of reinforcing the arena’s thick glass with a ballistic-resistant glaze shocked even Gehry’s own designers.

As we’ve been predicting, we see an ugly $500 milliion concrete box. Think Atlantic Terminal Mall, but as an arena.