Michael Phelan’s death was apparently no big deal.

The 28-year-old man was pronounced dead the evening of Sept. 29 at the Cook County Jail — the 17th person to die in custody there since Jan. 1, 2016.

“Foul play is not suspected, ” said Cara Smith, a top aide to Cook County Sheriff Tom Dart. “We will wait for the toxicology report and for the investigation by the Illinois State Police to conclude.”

Attempts to reach Phelan’s next-of-kin were unsuccessful, and it wasn’t clear where the dead man last lived.

      OPINION

Earlier this year, another inmate was found unresponsive on a transport bus to Stateville Correctional Center. Clifford V. Nelson, 49, was being transferred from the Cook County Jail when he died. Autopsy and toxicological reports concluded Nelson died from heroin, fentanyl and fentanyl analog overdose. His death was ruled an accident.

Lopez House, 47, collapsed and died at the jail on Aug. 20. Another detainee, Lindbert McIntosh, 57, died Aug. 5 while he was sleeping.

The deaths are under investigation.

Smith would not speculate on Phelan’s cause of death.

“From Jan. 1 of 2016 to the present, we have had 17 in-custody deaths,” Smith said. ” That includes everyone who had heart attacks, one suicide and all manners of death. We don’t know what he died of. That is what the investigation will tell us.”

Detainees, of course, are innocent until proven guilty and are supposed to be housed in a safe environment until they have their day in court.

Phelan wasn’t a stranger to the court system. He was on parole for a burglary involving a victim who was disabled or over 60 when he was arrested in March for another burglary, according to Smith.

The Illinois Department of Corrections determined he had violated his parole and took him into custody. He was returned to the Cook County Jail at the end of June and was in custody there until his death.

According to a source at the sheriff’s office, Phelan died after ingesting a “crushed” substance.

Smith said it’s “premature” to assume Phelan’s death was caused by a drug overdose and pointed out that everyone held at the jail has been in another law enforcement’s custody before getting there.

According to Smith, the Cook County Jail has recovered contraband this year that included the following: 147 plastic baggies of suspected cannabis; one folded piece of paper containing suspected heroin; three foil packets containing suspected hash; six baggies containing suspected cocaine; and a Kel-Tec 32-caliber handgun.

“If the system was working as it should, we shouldn’t ever find something,” Smith said. “It is very frustrating that this stuff gets through.”

Obviously, it would be nearly impossible to keep every bit of contraband from getting into the jail.

And drug overdose hasn’t been the most common cause of death at the Cook County Jail, according to a 2015 report by The Chicago Reporter.

Of the 72 people who died in custody at the Cook County Jail between 2009 and 2014, 70 percent died from chronic illnesses, and 19 percent were from suicides.

But from 2000 to 2015, more than half a million people nationwide died from drug overdoses, according to the U.S. Centers for Disease Control and Prevention.

The opioid crisis is likely affecting the jail population as well.

If Phelan died from a drug overdose, the jail would have a lot of explaining to do.