Just a few days after a paddleboarder’s mysterious death in Maine, state law enforcement authorities announced that they are still examining leads and advised local residents to stay alert.

“The Maine State Police acknowledges the anxiety and unease that this event has caused in the town of Union and among residents near Crawford Pond,” stated the Maine State Police in a release on Wednesday. “We are committed to thoroughly investigating the death of 48-year-old Sunshine Stewart.”

Stewart’s body was discovered on July 3 in Union, about 30 miles east of Augusta, following a report of a missing paddleboarder, according to state police.

An autopsy determined Stewart’s manner of death to be homicide, the agency said. Her cause of death has not been released. A state police official confirmed a report that Stewart was found “under unusual circumstances.”

The agency said the owners of a nearby campground have been cooperative with investigators and asked for information from anyone who saw Stewart paddleboarding between 6 p.m. and 9 p.m. July 2 near an island in Crawford Pond.

The agency has released few other details about her death, but said Wednesday that major crimes investigators have been examining all of the leads pushed through its tip line and continue to follow “every investigative and forensic avenue.”

A longtime friend of Stewart’s, Kimberly Hamill, told NBC News that it was “impossible” to make sense of her death.

“I grew up in Union, and as far I know, nothing like this has ever happened there,” she said. “For it to have happened to Sunshine is like, how could that even be? It just makes it feel like nothing will be right again ever.”

Hamill described Stewart as a solid friend who’d lived an incredible life: She was a carpenter who ran her own construction business. She was a boat captain who’d sailed to the Virgin Islands. She didn’t graduate high school but managed to earn a degree in marine biology, Hamill said.

“I want people to remember her as the force of nature that she was,” Hamill said. “She was such a loyal, good person. That was her most memorable quality — how much she believed in everybody.”