A 42-year-old man in a wheelchair should have spent a night in jail for a parole violation — but it turned into a 33-day death sentence in Rikers Island, a shocking new lawsuit alleges.

The siblings of Isa-Abdul Karim filed a wrongful-death suit in Manhattan federal court alleging that the “horrific” treatment he received in custody at the scandal-scarred jail complex resulted in his 2021 death.

He came down with COVID-19 after being crammed like a sardine for a week in a highly unsanitary holding cell with dozens of other unmasked detainees at the height of the pandemic — and then died from complications for which he received disastrous medical treatment, according to court papers.

The lawsuit, filed last month by Dhuha Abdul Karim and Tristan Ardrey, accuses the city Department of Correction, some of its employees, and others of “gross negligence.”

“As the COVID-19 pandemic raged inside the jails on Rikers Island, incarcerated people were forced to live in a medieval hellscape of disease, violence, and filth with little access to the basic necessities of life and deficient medical care,” the suit says.

It also claims staffers didn’t take his pleas for help seriously — despite Karim gasping for air shortly before collapsing and dying on Sept. 19, 2021. Karim had a history of serious medical conditions.

The suit alleges Karim was thrown in Rikers for “technical parole violations” in August 2021 and was only apprehended after being a victim of a stabbing.

Karim had been on supervised release since 2018 after previously serving time behind bars for selling cocaine to an undercover cop. However, a warrant was issued for his arrest in 2020 after Karim stopped meeting with a parole officer, according to the New York Times.

The suit seeks unspecified monetary damages. A Law Department spokesman said the suit is under review.