Missing teen Adriana Davidson, 15, is found dead three days after mysteriously vanishing from Ann Arbor school

A MISSING 15-year-old has been found dead three days after she vanished from school, her family has revealed in a heartbreaking video.

Adriana Davidson, known as Addy, from Ann Arbor, Michigan, was reported missing on Saturday at around 12am after she failed to return home from Pioneer High School.

On Monday afternoon, Adriana's brother shared an emotional video, revealing that his sister had been discovered dead by police.

"We got a call to get to my dad's apartment right away. The two detectives were there and they let us know that Adriana was found and that she has passed on," the victim's brother, Anthony Lopez, said in a Facebook post.

"My little sister is dead," Anthony said in his emotional video.

Police say Adriana was found under the bleachers at Pioneer High School and no foul play is suspected.

The teen's cause of death has yet to be determined.

Adriana's family last heard from her at about 9am on Friday, when she was headed to school.

Her father, John Davidson, reportedly was last in contact with her when she left to take a local public bus, known as The Ride, but she never returned later that day and didn't respond to his texts or calls.

"This is not my daughter," John told WXYZ. John said that Adriana always responds to him.

The worried father called Adriana's friends and went to the school, but couldn't find her.

When police checked surveillance footage from the bus she was on, they found out that Adriana arrived at school on Friday morning.

However, friends reportedly said that they last saw her at around 11am, outside the school, according to cops.

Her friends reportedly told police that she felt unwell.

Cops say the bus video then shows Adriana going back to school at around 12pm on Friday, but she never went inside.

This is the last time she was seen, wearing a green coat, black Ugg boots, and clear-framed glasses, according to police.

LAST TEXTS REVEALED

The teen's phone was reportedly found on the school's tennis courts on Friday afternoon by a student who then gave the phone to Adriana's best friend.

One of Adriana's best friends told the missing teen's brother, Anthony, that she saw Adriana leaving school on Friday.

She told Anthony that she reportedly texted Adriana and shared a screenshot of the text messages with Anthony.

"The text messages between her and her friend are time stamped at 12:26 p.m. where she had texted my sister saying 'You straight?' and then Addy responded saying 'No,'" Anthony told WXYZ.

The friend then reportedly replied: "Wym," which is an abbreviation for What do you mean? But Adriana never responded.

This is reportedly the last that anyone has heard from the missing teen.

Anthony told the outlet that the abandoned phone, which is now in police custody, was a "red flag."

"When I found out that Addy was potentially missing, I knew right away she didn’t run away. The red flag for me was the phone," he said.