dissenting.
I believe that the trial court was correct in striking expert Williams’ third statement of opinion. And since that opinion provides the only purported evidence that negligent maintenance of the sewer lines caused the non-scouring sewer plaintiffs’ flooding, the plaintiffs are unable to sustain a prima facie negligence claim and the defense is entitled to summary judgment.
Williams claims in his third opinion set that “HSD failed to clean its non-scouring sewers and keep these sewers free of accumulated debris, thereby reducing sewer capacity for plaintiffs!] connected to and upstream of non-scouring sewers and causing these sewage backups into plaintiffs’ homes which were connected to or upstream of the non-scouring sewers.” Appellants’ App. p. 1563-64. Williams opines that:
(a) the HSD failed to properly clean its non-scouring sanitary sewers within its sewerage system within the City of Hammond before July 26, 2007, (b) the HSD’s failure to properly clean its non-scouring sanitary sewers caused accumulated obstructions including but not limited to obstructive sludge, obstructive sediment, obstructive debris, and obstructive Fats, Oils and Greases (FOGS) to exist within its non-scouring sewers within its sewerage system on July 26, 2007, (c) these accumulated sewer obstructions were present on July 26, 2007 before the rainfall, (d) these accumulated sewer obstructions interfered with and prevented proper drainage of the HSD sewerage system by reducing the sewer water carrying capacity of the sewerage system and (e) these accumulated obstructions caused the sewage backups into these one-hundred-twenty-three (123) Retained Plaintiff Households’ homes and consequent injuries to these Plaintiffs on July 26, 2007 due to significantly reduced hydraulic capacity.
Id. at 1564. Williams explains that non-scouring sewer systems convey flows more slowly than scouring systems, so they are non-self-cleaning and require greater attention and maintenance. He introduces maps of Hammond’s non-scouring sewer lines. And he states that Hammond’s Chief of Sewer Maintenance (1) did not know what a non-scouring sewer was, (2) was unaware of the existence of non-scouring lines in various locales, and (3) consequently failed to conduct prudent cleaning of the non-scouring systems. Williams concludes that HSD “was negligent in failing to maintain a non-scouring main sewer listing and failing to inspect and monitor and, if needed, clean with greater frequency its non-scouring main sewers, significantly and substantially] causing the sewer water backups into the 123 Non-Scouring Sewer Plaintiff Households’ homes on July 26, 2007 and numerous other class members connected to or upstream of the non-scouring sewers.” Id. at 1569-70.
An expert witness must have “sufficient facts or data upon which to validly form an opinion.” Burp v. State, 612 N.E.2d 169, 172 (Ind.Ct.App.1993). “Free flowing speculation is just that and cannot be construed to be a fact that could shed doubt on the validity of other facts. Opinions expressing mere possibilities with regard to hypothetical situations are insufficient to establish a genuine issue of material fact.” C & C Oil Co., Inc. v. Ind. Dep’t of State Revenue, 570 N.E.2d 1376, 1379 (Ind. T.C.1991).
Williams’ third conclusion is inadmissible in my opinion because it hinges on an unsubstantiated statement of fact — namely, that debris had accumulated at the non-scouring sewer plaintiffs’ homes before the *86storm. Williams claims that “accumulated sewer obstructions were present on July-26, 2007, before the rainfall,” but he cites no basis for this assertion. There is no indication that he or anyone else observed the alleged obstructions. He notes that excessive debris was removed during general catchbasin cleaning in August, September, and October 2007, but he references no sources indicating that, among the many miles of Hammond sewer lines, debris was present specifically at or near the plaintiffs’ homes on the date in question. Cf. City of Bloomington Utils. Dept. v. Walter, 904 N.E.2d 346, 348 (Ind.Ct.App.2009) (in which sewer blockage was identified at plaintiffs’ home), trans. denied. Nor does he quantify the extent of the obstructions or illuminate the level of debris necessary to cause the backups sustained by the plaintiffs.
To make out a claim of negligent maintenance, the plaintiffs must establish that HSD breached an existing standard of care and that the breach proximately caused them injury. Williams may be qualified to testify that HSD breached a duty to properly maintain its non-scouring sewer lines. But without evidence of resulting obstructions at the plaintiffs’ households, Williams’ opinion that HSD’s negligence caused the plaintiffs’ flooding becomes nothing more than speculation. And with no competent evidence of causation in the record, the non-scouring sewer plaintiffs are unable to sustain a prima facie negligence claim. Accordingly, I believe there remains no genuine issue of material of fact and the defendants are entitled to judgment as a matter of law.
For these reasons I respectfully dissent and would affirm summary judgment in favor of the defense.