Investigations have begun in thedeathofToddlers & Tiarasstar Kailia Posey.

The Whatcom County Sheriff’s Office confirms to PEOPLE it is part of a multi-agency investigation related to the death of the 16-year-old former TLC star.

Washington State Patrol could not formally confirm the identify the subject of the death investigation as the individual is a juvenile, but did confirm to PEOPLE it is involved in an ongoing death investigation.

Washington State Parks Department also confirmed the investigation to PEOPLE.

Kailia Posey Facebook

Kailia Posey

Washington State Patrol Public Information Officer Trooper Jacob Kennett tells PEOPLE: “Yesterday on May 2 at about 1:26 p.m., Washington State Patrol was called to assist Whatcom Sheriff’s department to assist in a death investigation involving a minor at Birch Bay State Park.” Trooper Kennett adds it is an ongoing, multi-agency investigation.

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Other agencies involved include the Washington State Parks Department and the Blaine Police Department, where the park is located. PEOPLE has not yet received responses from the Blaine PD or the Whatcom County Medical Examiner.

Kailia Posey inToddlers & Tiaras.TLC

Kailia Posey

On Monday, Posey’s mother, Marcy Posey Gatterman, confirmed the news of her death viaFacebook. She was 16.

At the time, Gatterman shared a photo of Posey dressed in the sparkly gown she wore to prom last month.

Gatterman has not confirmed the cause of Posey’s death, but she has since updated her profile photo and cover image to honor her late daughter. For the profile image, she uploaded a photo of Posey as an angel.

PEOPLE has reached out to TLC for comment.

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Hours before confirming Posey’s death, Gatterman said the teenager was supposed to be “graduating with honors” next month.

Posey was best known for appearing on TLC’sToddlers & Tiaras, which originally aired from 2009 to 2013. The high schooler was 5 years old when sheappeared on one episodeof the reality series, which saw her compete in the California Tropic Arizona pageant, and she became one of the series' most recognizable faces after her reaction in an interview became a popular gif.

TLC

Kailia Posey

Posey continued to compete in pageants after her brief stint on the show. In January, sheannounced she was competingin Miss Washington Teen USA in February. “One word. Thankful,” she captioned a post onInstagram.

On Sunday, Posey hadlaunched an Instagram accountdedicated to showing off her contortion skills. However, her final post on her primary account wasa photo of herselfposing in a colorful, red outfit.

She captioned the pic, “None of your concern :).”

source: people.com