In Randy Russell v. Whirlpool Corporation (Dec. 17, 2012), No. 12-1451. In suit involving claims that a fire at plaintiffs' home was caused by defendant's defective refrigerator, the district court did not err in permitting plaintiff's expert to testify even though he had not followed NFPA 921 as the fire investigation standard is not the only reliable way to investigate a fire; our cases do hold that an expert who purports to follow NFPA 921 must follow its contents reliably if his testimony is to be admitted, but here the expert did not purport to apply NFPA 921 and his testimony could not be excluded for failure to reliably follow the contents of the standard; district court did not err in determining the expert followed a reliable methodology in his investigation; Missouri law permits a jury to infer a product defect and causation based on circumstantial evidence under a res-ipsa loquitur theory.