Police were awaiting autopsy results this week to determine whether a strong pain killer responsible for a rise in overdose deaths across the nation caused the death of a maintenance worker Dec. 23 at Fallon Middle School in Dublin.

Police said the drug fentanyl was found at the scene.

The victim, James Covington, 32, of Pittsburg, died shortly after he and a 29-year-old woman, identified as his fiancée, were discovered unconscious at 7 a.m. in the campus library, police said.

Dublin police officers went to the campus to investigate a missing persons’ report. The couple, who had two young children — at least one of them together — had failed to return home from their Tuesday evening maintenance shift from 3 to 8 p.m., Dublin police Capt. Nate Schmidt said.

Officers found a car belonging to the pair parked outside the school, then located the victims suffering from medical issues in the library.

As the officers entered the room and carried the victims out, they reported detecting a chemical smell.

Alameda County paramedics arrived to treat the pair. The woman was taken to a hospital, but Covington was pronounced dead at the scene.

Alameda County Fire hazardous materials specialists examined the library and campus, but did not find any dangerous chemicals, Schmidt said.

What caused that smell was not clear, and it was undetermined what the officers had detected, Schmidt said. Officers found fentanyl at the scene, but he declined to say where.

Fentanyl is a synthetic opioid pain reliever used for treating severe pain, usually in advanced cancer patients.

The Centers for Disease Control and Prevention's website describes fentanyl as 50 to 100 times more potent than morphine. Normally prescribed in skin patches or lozenges, it also can be misused and abused.

In recent years, a rise in overdoses and deaths in the United States are tied to illegally manufactured opioids, including fentanyl. Users like its heroin effect, often mixing it with heroin and cocaine for a feeling of euphoria, the CDC said.

In 2018, more than 31,000 people died in the United States from overdoses involving synthetic opioids, including fentanyl, but excluding methadone.

Preliminary tests showed the drug found at the scene was fentanyl, Schmidt said. Alameda County Coroner’s Bureau officials scheduled Covington’s autopsy for this week. Toxicological tests for narcotics often can take weeks to perform.

Schmidt called Covington’s death a “complete tragedy.”

“Our hearts go out to the family,” he said.

The woman’s condition was not released, but Schmidt said she was expected to recover.

In a memo to school staff, Dublin Unified School District Interim Superintendent Daniel Moirao described the victims as "part of our site custodial team."

"Our deepest sympathies go out to the family and friends of our lost colleague and also to the students, staff and community of Fallon Middle School," Moirao wrote. "No matter how strong the Fallon Mustang family is, losing a family member at any time is tragic, but during this time of year, it is devastating."

The district made counselors available for students and staff.

Saying "speculation helps no one," Moirao asked staff to wait for facts to come from the police and authorities about the deaths.

"I know that this has been a tough year for our community," he said. "If we have learned anything in 2020, it is to appreciate what we have and to remember to tell our family and friends that we love them."