Officials closed a river in California citing toxic algae weeks after a family of 3 was mysteriously found dead nearby

• A family of three and their family dog were found dead on a hiking trail last month in California.
• The deaths mystified officials, who could not determine the cause of death.
• Now the Bureau of Land Management has closed areas along a nearby river that has potentially toxic algae blooms.

Two weeks after a family of three was found dead on a hiking trail in Northern California, the nearby river area has been closed due to toxic algae, officials said Friday.

The Bureau of Land Management issued an emergency closure order for campgrounds and day-use areas located along a 28-mile stretch of the Merced River.

"The safety of visitors to our BLM-managed public lands is a top priority," Elizabeth Meyer-Shields, a field manager for BLM, said in a statement. "These algal blooms can produce toxins that can make people and pets extremely sick. We will continue to monitor for the algae's presence and look forward to when the public can safely recreate in the Merced River."

On August 17th, the bodies of John Gerrish, Ellen Chung, their one-year-old daughter, Miju, and their dog were found on a trail close to the river in the Sierra National Forest. Officials were mystified by the deaths.

Mariposa County Sheriff Jeremy Briese said at the time there was no obvious cause of death and no signs of blunt-force trauma, calling it the first incident like this he had seen in his 20 years on the job.

"I've worked in different capacities but I've never seen a death like this," Briese told KSEE.

Kristie Mitchell, a spokesperson for the Mariposa County Sheriff's Office, told the San Francisco Chronicle the case was a "very unusual, unique situation."

Officials have still not determined a cause of death, but have said they were considering whether toxic algae in the river played a role. Days after the bodies were found, the area was designated a hazmat site.

The BLM-managed areas along Merced River will remain closed until at least September 17.