concurring.
I respectfully concur.
The court correctly overrules appellants’ third issue and holds that, presuming the trial court erred as asserted in appellants’ other three issues, the alleged errors probably did not cause the rendition of an improper judgment because there is no legally sufficient evidence of causation. See Tex.R.App. P. 44.1; Case Corp. v. Hi-Class Bus. Sys. of Am., Inc., 184 S.W.3d 760, 784 (Tex.App.-Dallas 2005, pet. denied). I write separately to specifically address the evidence appellants cite as raising a fact issue as to proximate cause.
Appellants’ only expert regarding the cause of the explosion was Georges Mel-*821hem, and his testimony is the only evidence that arguably could raise a fact issue as to proximate cause. Though appellants cite various parts of Melhem’s testimony concerning Kellogg’s alleged negligence, the following excepts are the only cited parts in which Melhem arguably addresses causation:
Q. All right. The third opinion.
A. If Kellogg engineers recognized the reactivity of [butadiene] they would have required the use of additional engineering controls to prevent this incident.
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Q. Do you also believe that Kellogg was a cause of this incident?
A. Yes.
Q. Based on everything that you have seen in this case, your knowledge, your experience, your review of the standards, the industry practices, was the failure of Kellogg to provide an adequate system, layers of protection a proximate cause of this incident?
A. I’m just reading the definition. Yes, the answer is yes.
This testimony is conclusory and is not legally sufficient evidence that Kellogg’s alleged negligence was a proximate cause of the explosion. See Coastal Transport Co., Inc. v. Crown Cent. Petroleum Corp., 136 S.W.3d 227, 232 (Tex.2004) (stating that conclusory or speculative expert testimony is not legally sufficient). Furthermore, the butadiene tank in question had a pressure safety valve — a safety device designed to protect the tank from fading due to overpressure. Phillips disabled this valve before the explosion.
The majority correctly notes that Mel-hem did not identify any specific combination of pressure detection, relief, and warning devices that actually would have prevented the explosion and resulting injuries. In addition, Melhem did not testify that Kellogg should have designed or recommended a system that would have been incapable of being disabled by Phillips’s employees. Even if some of the systems Melhem generally described were automatic, they would not have eliminated the potential for human error because, just as Phillips’s employees disabled the pressure safety valve, they could have disabled or deactivated the described systems. It is evident from the circumstances surrounding the explosion that Phillips would have deactivated whatever pressure-relief devices were present for the butadiene tank in question.1
For the foregoing reasons, the evidence is not legally sufficient to support a finding that Kellogg’s alleged negligence was a proximate cause of the explosion. Thus, even if the trial court erred as appellants assert in their other issues, the errors would be harmless.
. See Arguelles v. Kellogg Brown & Root, Inc., 222 S.W.3d 714, 728-31 (Tex.App.-Houston [14th Dist.] 2007, no pet.) (discussing similar issue regarding same explosion and same defendant in a different case, in which the summary-judgment evidence was not the same as the evidence at trial in this case).