We were recently involved in a case involving whether the installation of an underground storage tank was done properly. The plaintiff removed the tank and replaced it about six months after they had filed suit against the installers. The plaintiff, however, failed to notify the defendant (or its lawyers) that the tank was going to be removed. As a result, the defendant was denied an opportunity to inspect the condition of the tank and the surrounding soil conditions (which was the seminal evidence in the case). The court ultimately dismissed the plaintiff's case, in its entirety, because its actions denied the defendant access to the tank. It is also notable that the plaintiff did a poor job documenting the removal process and appeared to breach industry standards when it failed to preserve evidence.
In short, before you take steps to remedy an issue, be careful that you do not destroy evidence, or at least take steps to document the evidence. The duty to preserve evidence in most jurisdictions arises when a person reasonable should know of the existence of a claim. In our case, there was no issue on that, as a lawsuit had already been filed. Matters can get a little tricky when it is pre-litigation and there could be a disagreement as to whether litigation is likely. As always, an ounce of prevention is better than a pound of cure and you should make a quick call to your lawyer if you have any questions about your duty to preserve evidence.