This is an appeal by the plaintiff from a judgment for the defendant in a personal injury action.
The facts were stipulated. Appellee’s agent violated a traffic ordinance of the District of Columbia1 by leaving appellee’s truck unattended in a public alley, with the ignition unlocked and the key in the switch. He left the truck outside a garage “so that it might be taken inside the garage by the garage attendant for night storage,” but he does not appear to have notified anyone that he had left it. Within two hours an unknown person drove the truck away and negligently ran over the appellant.
The trial court duly directed a verdict for the appellee on the authority of Squires v. Brooks.2 That case was decided in 1916. On facts essentially similar to these, and despite the presence of a similar ordinance, this court held that the defendant’s act in leaving the car unlocked was not a “proximate” or legal cause of the plaintiff’s injury because the wrongful act of a third person intervened.3 We cannot reconcile that decision with facts which have become clearer and principles which have become better established than they were in 1916, and we think it should be overruled.
*15Everyone knows now that children and thieves frequently cause harm by tampering with unlocked cars. The danger that they will do so on a particular occasion may be slight or great. In the absence of an ordinance, therefore, leaving a car unlocked might not be negligent in some circumstances, although in other circumstances it might be both negligent and a legal or “proximate” cause of a resulting accident.4
But the existence of an ordinance changes the situation. If a driver causes an accident by exceeding the speed limit, for example, we do not inquire whether his prohibited conduct was unreasonably dangerous. It is enough that it was prohibited. Violation of an ordinance intended to promote safety is negligence. If by creating the hazard5 which the ordinance was intended to avoid it brings about the harm which the ordinance was intended to prevent, it is a legal cause of the harm.6 This comes only to saying that in such circumstances the law has no reason to ignore and does not ignore the causal relation which obviously exists in fact. The law has excellent reason to recognize it, since it is the very relation which the makers of the ordinance anticipated. This court has applied these principles to speed limits and other regulations of the manner of driving.7
The same principles govern this case. The particular ordinance involved here is one of a series which require, among other things, that motor vehicles be equipped with horns and lamps. Ordinary bicycles are required to have bells and lamps,8 but they are not required to be locked. The evident purpose of requiring motor vehicles to be locked is not to prevent theft for the sake of owners or the police, but to promote the safety of the public in the streets. An unlocked motor vehicle creates little more risk of theft than an unlocked bicycle, or for that matter an unlocked house, but it creates much more risk that meddling by children, thieves, or others will result in injuries to the public. The ordinance is intended to prevent such consequences. Since it is a safety measure, its violation was negligence.9 This negligence created the hazard and thereby brought about the harm which the ordinance was intended to prevent. It was therefore a legal or “proximate” cause of the harm.10 Both negligence and causation *16are too clear in this case, we think, for submission to a jury.
The fact that the intermeddler’s conduct was itself a proximate cause of the harm, and was probably criminal, is immaterial. Janof v. Newsom11 involved a statute which forbade employment agencies to recommend servants without investigating their references. An agency recommended a servant to the plaintiff without investigation, the plaintiff employed the servant, and the servant robbed the plaintiff. This court held the agency responsible for the plaintiff’s loss. In that case as in this, the conduct of the defendant or his agent was negligent precisely because it created a risk that a third person would act improperly. In such circumstances the fact that a third person does act improperly is not an intelligible reason for excusing the defendant.12
There are practical as well as theoretical reasons for not excusing him. The rule we are adopting tends to make the streets safer by discouraging the hazardous conduct which the ordinance forbids. It puts the burden of the risk, as far as may be, upon those who create it. Appellee’s agent created a risk which was both obvious and prohibited. Since appellee was responsible for the risk, it is fairer to hold him responsible for the harm than to deny a remedy to the innocent victim.
Reversed.