In Buchanan v. Rose, 138 Tex. 390, 159 S.W.2d 109 (1942), a truck driver drove his truck over a bridge causing the bridge to collapse, though the driver of the truck was not negligent. Another driver stopped the truck driver, told him the bridge had collapsed and that he ought to put some warning signs up. Id. The truck driver said he did not have time to place any warning signs, and indeed, did not place any warnings. Id. Six days later, the Buchanans ran onto the broken bridge and, without any negligence on their part, Mrs. Buchanan was severely injured. Id. A jury found that the truck driver was negligent, and the trial court rendered judgment for the plaintiffs. Id. The court stated: It is a well-understood rule that negligence is the doing of that which an ordinarily prudent person would not have done under the same or similar circumstances, or the failure to do that which an ordinarily prudent person would have done under the same or similar circumstances. Here we are not concerned with any supposed negligence on the part of the defendant in doing something which he should not have done, for it is conceded that he was not negligent in breaking the bridge down. If the driver of the truck was negligent at all, it was because of his failure to do something-to give warning of the broken bridge. Before we can determine whether he was negligent in failing to give warning, we must first decide whether he owed the legal duty to do so. There are many instances in which it may be said, as a matter of law, that there is a duty to do something, and in others it may be said, as a matter of law, that there is no such duty. Using familiar illustrations, it may be said generally, on the one hand, that if a party negligently creates a dangerous situation it then becomes his duty to do something about it to prevent injury to others if it reasonably appears or should appear to him that others in the exercise of their lawful rights may be injured thereby. On the other hand, it may be said generally, as a matter of law, that a mere bystander who did not create the dangerous situation is not required to become the good Samaritan and prevent injury to others. Under the last rule, a bystander may watch a blind man or a child walk over a precipice, and yet he is not required to give warning. He may stand on the bank of a stream and see a man drowning, and although he holds in his hand a rope that could be used to rescue the man, yet he is not required to give assistance. He may owe a moral duty to warn the blind man or to assist the drowning man, but being a mere bystander, and in nowise responsible for the dangerous situation, he owes no legal duty to render assistance. We think it may also be said that if one by his own acts, although without negligence on his part, creates a dangerous situation in or along a public way and it reasonably appears that another in the lawful use of such way in the exercise of ordinary care for his own safety may be injured by the dangerous situation so created, the one creating the same must give warning of the danger or be responsible for the consequences. To illustrate: One who in the exercise of a lawful right, and without negligence on his part, makes an excavation across a street or sidewalk or on his premises in close proximity to a public way, or parks a vehicle in a road, or otherwise obstructs the road with a foreign substance, is bound to give warning of the danger created thereby. Likewise, it has been held that one who, without negligence, strikes a trolley pole with his automobile and causes it to fall across the road is liable for failure to protect others from injury thereby. It will be noted, however, that in each of the above instances the defendant by his own act created the dangerous situation. In the case at bar, it is hardly fair to say that the defendant's agent created the dangerous situation. The bridge was already in a defective condition. It was insufficient in strength to carry a normal load. It merely gave way as the result of the usual and legitimate use of the road. It fell as a result of its own inherent defects. Defendant was merely the victim of a defective condition that already existed. It would be carrying the matter too far to say that one must give notice of every known defect in a road naturally resulting from his normal and legitimate use thereof. To so hold would make the use of the highways too hazardous from the standpoint of public liability. (Buchanan, 159 S.W.2d at 110-11.) Ultimately, the court held that because the driver did not create the dangerous condition, he had no duty to warn the public of it. Id.