MADISON, Wis. -

The local medical examiner and public health experts are refuting rumors in Stoughton that a blue-green algae outbreak contributed to the deaths of two teenage girls last week.

Emma Maurer, 16, and Sydnie Kwiatkowski, 15, were found dead in Lake Kegonsa last Friday after a daylong search. The Dane County sheriff later said it appeared to be an accidental drowning, but a cause of death won't be released for several more days.

Residents in Stoughton, looking for answers after the deaths, are saying the toxic algae may have played a role, said Lori Jeppson, who lives on the lake. Jeppson shared photos that she took the day the girls died, depicting algae she said was the worst she'd ever seen.

"I just got back and heard there were concerns that the girls had gotten overcome by the toxins in the algae, and maybe that had something to do with drowning or maybe getting sick and not being able to get back to shore," Jeppson said. "It's a big rumor, and the people I've all asked have all heard it."

The Dane County medical examiner took note of the concerns, asking for extra samples of the waters near where the girls died. But, it's highly unlikely that blue-green algae was a factor, because both girls would have needed to suffer a severe allergic reaction at the same time, the examiner's office said.

Others said they don't think the girls or any other swimmers would have gotten near the slick bacteria because of its appearance.

"It's visually so unattractive," said Kirsti Sorsa, a lab director with the Public Health Department of Madison and Dane County. "It's hard to imagine that people would swallow that much of the water."

The bacteria, which shows up in sheltered areas of southern Wisconsin lakes in the summer, isn't immediately deadly, she said. But, people should stay away it they see it, because blue-green algae is dangerous, Sorsa said.

"The conditions can vary widely over time," she said. "Whenever people see that, it should be a sign that they should stay away from the bloom and avoid the area. Keep kids and pets away."

On Lake Kegonsa, a community is still grieving with the death of the two teens. Memorials still stand in LaFollette Park, near where the girls died.

Community members are just looking for answers, Jeppson said.

"It's a huge shock for our community. It's really sad, and I think we're really affected by it," she said.