Laval police say they have found the body of a 14-year-old girl who had been missing since Monday.

Athena Gervais's body was recovered late Thursday afternoon in a stream behind her high school in Fabreville, in northwest Laval.

A firefighter who was part of a search team made the discovery.

"We will try to understand the cause and the circumstance as to what happened," said Laval police spokesperson Const. Stéphanie Beshara.

Police investigators in Laval are looking for clues near the stream, in back of École Poly-Jeunesse, where the body of Athena Gervais was found Thursday afternoon. ( Benoit Ducharme/Radio-Canada) Gervais's death is being treated as a suspicious death at this point until investigators can uncover more information.

Last seen on lunch break

Gervais had last been seen Monday, leaving École Poly-Jeunesse at lunchtime. She didn't return to school in the afternoon, and she never showed up at home later.

According to police, she did not have a history of running away from home.

Her body was found a day after investigators set up a command post near the school. Beshara said even though helicopters and search dogs were used, there was no sign of Gervais on Wednesday.

"The body was not visible from the site."

The school will be open Friday. The Laval School Board told CBC it would be too last minute for parents to make alternate arrangements if classes were to be cancelled. Support staff will be on site to help students.