1999 Plymouth Voyager shattered

I am in need of help. Apparently my transmission has blown (literally) and now according to my dad there are metal pieces in near the flywheel and near other stuff. Is there anyway that you can give me an approximate estimate of what it will cost to fix it. And tell me how this is possible. There were no warning signs that I noticed. My check engine light never came on, there was no knocking or anything else out of the ordinary. However, when it happened there was a loud clanking and banging noice and then my van stalled out and woud not go back into gear. Please help.