even if only part of them went off, it was going to scatter debris from the device in all directions. But it was still 5 tons of high-explosives. If the high explosives were not properly synchronized or if any failed, then it was unlikely for the plutonium core to achieve a nuclear reaction. High explosives were set off to compress a plutonium core and go nuclear. The Trinity device was an implosion-design nuclear bomb. I don't think I found what you're looking for, but I suspect there were contingency plans that were made but never published or discussed in detail.
