I learned an important lesson a few years ago: sometimes you can't make something better, and trying to make it better only makes it worse.
Stop, regroup with others and get a proper plan together.
My suggestion would be to acknowledge the issue, let people know you will address it shortly but you need time to talk with your partners so you could get a proper response together.
Perhaps some version of "we're going to get to the bottom of this." Sure, it could be deemed a short term cop-out but it's better than sticking your foot in your over and over.
I'm curious how public relations experts recommend people handle a situation like this.