BAY COUNTY, Mich. -- Sheriff’s deputies and investigators said they found the body of an Oakland County woman who has been missing since Thursday.

Emily Jane Plouffe-Simunic, 29, was found Tuesday just off the northbound side of Interstate 75 at the U.S. 10 interchange.

Investigators said her car went off into a densely wooded area, not visible from the roadway.

Detectives and State troopers are working to determine the circumstances that led up to the fatal crash.

An autopsy has been performed but failed to reveal a definitive cause of death.

Investigators said they will be waiting for the results of toxicology testing, which could take several weeks, before a final cause of death is determined.

Authorities said they have not seen anything that leads them to believe Simunic’s death was anything other than an accident.

Police said Simunic was heading to West Branch to meet up with some friends.

But when she didn't know show up, call or text, her family and friends knew something was wrong.

That’s when the Oakland County sheriff's department launched an investigation.

Investigators tracked Simunic's cell phone signal to a tower near the Zilwaukee Bridge in Bay City.

Detectives noticed a disturbed tree near the highway and that's where they found the registered nurse’s body lying next to her 2003 Volkswagen Jetta.

Family members said it appeared Simunic had an accident and veered off the road.

Stay with WNEM.com and TV5 as more information becomes available.