WASHINGTON — Montgomery County’s police chief says social media helped investigators build a timeline of the night a Bethesda teen went missing and then helped lead officers to the woods where they found his body.

Montgomery County Police Chief Tom Manger said police are still investigating how 17-year-old Navid Sepehri ended up dead behind the popular Bannockburn Swim Club.

“We are still waiting for the medical examiner. We’ve gotten some preliminary information, and it does look like it was accidental,” Manger said of Sepehri’s’s death.

Manger said the police will also perform toxicology tests to determine Sepehri’s cause of death.

“It’s interesting that through social media we were able to get some information about where he may have been … as well as the last location where his phone was pinging from,” Manger said to WTOP.

Sepehri was a senior at Walt Whitman High School. WTOP’s news partner NBC Washington reports he was at a party the night he died.

“He was out, his friends knew,” Manger said.

The teen was reported missing around 11:30 p.m. Saturday after he didn’t return home, police said.

A support team of psychologists was at the school Monday to provide counseling to students, Alan Goodwin, Walt Whitman’s principal said in a letter to parents.