A California mother is accused of not calling 911 as her 16-year-old son overdosed—and ultimately died—on fentanyl-laced Xanax.

KRON reported that Danielle Foernsler, 34, and her friend, Robert D. Harrison, 39, were arrested after Harrison’s roommate called 911 Monday morning and reported that the teen was having a seizure. The roommate claimed he had just awoken and saw Harrison and another person, presumably Foernsler, loading the teen into a car.

Police who responded to the Petaluma home found the unresponsive teen. The boy was rushed to the hospital where he was pronounced dead at 5:09 a.m. Police said the preliminary cause of death is a drug overdose, according to the news station.

Responding officers noted that Foernsler, a transient, and Harrison both appeared to be under the influence of narcotics. Officers also claimed Harrison had a loaded firearm and a loaded syringe, according to SF Gate.

Police said Foernsler initially gave officers a fake name and claimed to be the teen’s cousin. She reportedly admitted to being the teen’s mother and claimed that he was in possession of Xanax laced with fentanyl.

However, according to The Press Democrat, the pair was also found with heroin.

“All three were being used. We’re not sure who was using what,” Petaluma police Lieutenant Tim Lyons said.

The pair is accused of leaving the dying teen in the car and fleeing right before officers arrived. Once they noticed that the teen was overdosing, Lyons claimed they put him in the shower instead of calling 911.

Harrison was charged with child endangerment, gun and drug possession, and being under the influence of a narcotic. Foernsler was arrested on suspicion of manslaughter, felony child endangerment, and two robbery warrants.

Harrison was released from jail as of Tuesday. Foernsler is being held without bail.

[Featured Image: Danielle E. Foernsler/Sonoma County Sheriff’s Office]