Opposing attorneys agree that the amoeba that killed 9-year-old Jack Ariola Erenberg after he swam in Stillwater's Lily Lake was invisible to the human eye. But they differ strongly about the legal significance of that.
In their second court hearing of the summer, they argued over whether the amoeba was an artificial or natural organism in Lily Lake and why that should matter.
"The whole case turns on the hidden nature of the shallow water," said Roger Strassburg, who filed the wrongful death suit in December on behalf of Jack's father, Jim Ariola.
Jack, of Stillwater, died from a rare parasite in August 2012 after swimming in Lily Lake, which has a small beach. His death came two years after Annie Bahneman, 7, of Stillwater, also died from the Naegleria fowleri amoeba, which was traced to her swimming in the same lake. The parasite, found in warm freshwater and soil, causes a rare but severe brain infection that is nearly always fatal.
The suit alleges that after Annie died, the city of Stillwater, Washington County and the Minnesota Department of Health should have issued warnings of the amoeba's apparent presence in the lake and its potential for harm.
Shallow water on the beach created "an artificial hot zone" where amoeba assumed a deadly, pathogenic form, Strassburg said in the Sept. 13 hearing in Washington County District Court. There were no public warnings.
The suit claims that excessive stormwater runoff from residences and streets surrounding Lily Lake, in the heart of Stillwater, warmed the water to an extent that the amoeba could thrive.
Jennifer Coates, an assistant attorney general representing the Health Department, said she didn't understand why the state would have responsibility for stormwater runoff in Stillwater.
"It naturally happens when it rains next to a lake anywhere in the world," Coates told District Judge Susan Miles.
There's no question the amoeba caused Jack's death, said Pierre Regnier, the attorney representing Stillwater.
"It was not only hidden to Jack, to the adults who were supervising him, it was hidden to everybody in the world," Regnier said. "There's no way in God's green earth that the city of Stillwater would create an amoeba. We have no knowledge of an invisible condition existing in our lake."
Scott Anderson, representing the county, said Strassburg's latest motion introduced nothing new. "I don't even know why I'm here," he told the judge. "He's only repackaged the original complaint."
All three agencies have asked the court to dismiss the suit.
Strassburg said adults who accompanied Jack when he swam in Lily Lake heeded a warning sign about drowning and made him wear a life vest. Because of that, he said, they would have obeyed a warning sign about dangers of amoeba had one existed, he said.
At a public meeting in Stillwater after Jack's death, a state health official said that many Minnesota lakes could have the parasite — particularly in prolonged stretches of summer heat — and that it can come and go unpredictably.
"It's not something that's quickly detectable, and it's not something that's going to be consistent," Jim Koppel, deputy commissioner at the state health agency, said then.
Lily Lake was closed to swimming after Jack died, but the Health Department said amoeba could be found in warm water anywhere, and swimmers should not assume that closing one lake meant others were safe.
Also cited in the Ariola suit, although not part of it, was the case of 12-year-old Hailee LaMeyer of Stacy, Minn., who died in 2008 after swimming in Fawn Lake near her home.
Miles said she would rule on the latest motion in 90 days.