Lolz... Things like these happens for no reason. Btw, is it the mud due to which you guys lost traction or is it due to some electrical/engine failure. Use a snorkel next time.
My grandfather's W116 went out of control back in mid 90s and took a dive in a canal off a bridge. Thanks God he and his driver both came out well.
A friend dived into a giant ditch full of rain water at night on main Shaheed-e-Millat Road, Karachi in his Cruising. He went out of the car by sunroof as water was around couple of feet above the roof.