concurring.
I agree that the manslaughter convictions must be affirmed; however, I reach this conclusion based on a different view of the evidence than that taken by the majority. I believe that the only evidence upon which these convictions can stand is the evidence regarding Jetton’s consumption of alcohol and the effect that it *562had on him. Because the majority also relies upon evidence regarding the speed of Jetton’s truck, the number of persons in the vehicle, and the fact that it had failed inspection, I write separately.
The Virginia Supreme Court has held that “involuntary manslaughter arising from the operation of a motor vehicle should be predicated solely upon criminal negligence proximately causing death.” King v. Commonwealth, 217 Va. 601, 607, 231 S.E.2d 309, 316 (1977). In such cases, involuntary manslaughter is defined as “the accidental killing which, although unintended, is the proximate result of negligence so gross, wanton, and culpable as to show a reckless disregard of human life.” Id.
From this it is apparent that the Commonwealth must establish, beyond a reasonable doubt, both that the defendant was guilty of criminal negligence and that such negligence was the proximate cause of death. Failure to establish either of these elements must result in a verdict of not guilty. In the present case, I believe that the only evidence which attains that end is the evidence regarding Jetton’s consumption of alcohol and its resulting effect on him. There was no evidence from which the jury could have concluded, without resort to speculation, that Jetton’s continued driving of his truck after it had failed inspection was the proximate cause of the accident. Neither could the jury have properly concluded from the evidence that Jetton lost control of his vehicle as a result of excessive speed or the number of occupants in the vehicle.
Viewed in the light most favorable to the Commonwealth, the evidence established that Jetton had consumed approximately five and one-half twelve ounce beers over a nine hour period preceding the accident. While I do not believe that this amount consumed over the period of time in question gave rise to an inference of intoxication, it was nevertheless a relevant circumstance for the jury to consider in determining whether Jetton was guilty of criminal negligence. Beck v. Commonwealth, 216 Va. 1, 5, 216 S.E.2d 8, 10 (1975); Simon v. Commonwealth, 220 Va. 412, 420, 258 S.E.2d 567, 573 (1979).
Evidence was presented that approximately two hours before the accident Jetton’s speech had been affected. Specifically, Bonnie Ryder, who was a friend of Jetton’s and who had spoken with him by phone many times, testified that on this evening when she *563talked to him around midnight: “He sounded different. He ... I don’t know. He was a little bit slurred, but nothing bad, just sounded different than before.” While this testimony was hardly conclusive, I am unable to find that it was insufficient as a matter of law on which to base a conclusion that Jetton had been affected by the alcohol.
Finally, there was the testimony of a rescue squad worker who stated that he smelled a moderate amount of alcohol on Jetton’s breath at the scene of the accident. It is well established that the mere odor of alcohol is insufficient to establish either intoxication or negligence. Baker v. Taylor, 229 Va. 66, 69, 326 S.E.2d 669, 671 (1985). However, it is equally well established that this rule does not apply where, as here, the odor of alcohol is combined with evidence that the defendant’s manner, disposition, speech, muscular movement, general appearance or behavior have been affected. Id.
The jury was therefore justified in concluding that Jetton was driving his truck while under the influence of alcohol, although perhaps not legally intoxicated, and that this impaired his capacity “to perceive the dangers with the clarity, make decisions with the prudence, and operate the vehicle with the skill and caution required by law.” Simon, 220 Va. at 419-20, 258 S.E.2d at 572-73. As stated in King: “[D]riving under the influence of intoxicants which proximately results in death constitutes involuntary manslaughter.” 217 Va. at 606, 231 S.E.2d at 316 (citing Beck v. Commonwealth, 216 Va. 1, 216 S.E.2d 8 (1975); Albert v. Commonwealth, 181 Va. 894, 902, 27 S.E.2d 177, 180 (1943)).
Having concluded that Jetton was driving while impaired by alcohol, the jury could further have concluded that this was the proximate cause of the accident. Although Jetton believed that one of his passengers may have interfered with his driving, the jury was not bound to accept this. Without Jetton’s explanation, the evidence showed that the truck went off the road at a curve which was clearly marked by a directional arrow and a 50 mph cautionary sign. Jetton testified that he was familiar with the road, having driven it nearly every day for the preceding seven years.
The mere happening of an accident does not explain the cause of the accident. Bacon v. Commonwealth, 220 Va. 766, 769, 263 *564S.E.2d 390, 392 (1980). However, in this case the evidence of impairment from alcohol when combined with the failure of Jetton to negotiate a well-marked curve he had driven many times raised a sufficient inference from which the jury could reasonably have concluded that the accident was either caused or exacerbated by Jetton’s conduct. It is the element of impairment from alcohol which separates this case from Bacon and Powers v. Commonwealth, 211 Va. 386, 177 S.E.2d 628 (1970)(mere happening of an accident does not give rise to an inference of reckless driving).
The majority, however, not only relies upon this evidence, but also upon evidence that Jetton’s truck had failed inspection and that it was going slightly in excess of the speed limit as it was sliding across the road. I do not believe that this evidence can be relied upon to sustain the convictions because neither of these factors was shown to have contributed towards causing the accident.
The evidence showed that Jetton’s truck had failed inspection nearly a month prior to the accident. The mechanic who conducted the inspection testified that the front brake pads were worn out, though not completely. In addition, there was an unspecified problem with the steering. Jetton testified that this problem was a missing lug. An accident reconstruction team investigated the accident. Two members of this team testified. Neither stated that the brakes on Jetton’s truck had failed, or that this or any other mechanical failure contributed to the accident.
Regarding the issue of speed, one of the accident experts testified that from various physical evidence gathered at the scene, he could estimate the speed of Jetton’s truck to have been 57 mph at the time it re-entered the road, after having initially failed to negotiate the curve. The speed limit on this road is 55 mph, although at the curve there is an advisory 50 mph sign. The expert could not estimate the speed of the truck at the time it left the road, nor was there other evidence on this point. Given the fact that the curve where the truck initially went off the road is at the top of an incline and that there was no evidence of braking, it would be speculative to conclude that Jetton was traveling at excessive speed when he went off the road.
Proximate cause is as much an element of involuntary manslaughter as is criminal negligence. The Commonwealth must prove both elements beyond a reasonable doubt. The Supreme *565Court has recently explained in a civil case that in establishing proximate cause the moving party “must show how and why the incident happened. And if the cause of the event is left to conjecture, guess, or random judgment, the plaintiff cannot recover.” Lawrence v. Snyder, 229 Va. 139, 142, 326 S.E.2d 690, 692 (1985). If this is true in a civil case, it is no less so in a criminal case.
I believe that without a showing of how or why the truck’s speed during its slide, its failure to pass inspection, or its number of occupants, contributed as a cause of the accident, these factors amount to nothing more than conjecture, guess or random judgment. However, I believe that the conviction must be affirmed because the evidence of alcohol consumption, combined with evidence that it affected Jetton’s speech, was not insufficient as a matter of law to substantiate a finding that his operation of the vehicle constituted criminal negligence, proximately causing the death of five occupants of his vehicle.