As part of the requirements to get a degree in engineering, I had to take an ethics course. Engineers are all bound my the code of ethics. Listing a few relevant points from here:
III. Professional Obligations
1. Engineers shall be guided in all their relations by the highest standards of honesty and integrity.
a. Engineers shall acknowledge their errors and shall not distort or alter the facts.
b. Engineers shall advise their clients or employers when they believe a project will not be successful.
5. Engineers shall avoid all conduct or practice which deceives the public.
As far as my ethics course was concerned, your obligation here to inform the injured parties was required. Documenting what went wrong but not notifying the injured parties was not acceptable, and to my understanding you would indeed be liable in such a situation.
Slashdot Mirror
III. Professional Obligations
1. Engineers shall be guided in all their relations by the highest standards of honesty and integrity.
a. Engineers shall acknowledge their errors and shall not distort or alter the facts.
b. Engineers shall advise their clients or employers when they believe a project will not be successful.
5. Engineers shall avoid all conduct or practice which deceives the public.
As far as my ethics course was concerned, your obligation here to inform the injured parties was required. Documenting what went wrong but not notifying the injured parties was not acceptable, and to my understanding you would indeed be liable in such a situation.