It is “unconscionable” and “absolutely unacceptable” that a Brooklyn funeral home left corpses in storage vans as the city’s mortuary system is overwhelmed with coronavirus patients, Mayor Bill de Blasio said Thursday.

“Why on earth did they not either alert the state who regulates them or go to the NYPD precinct and ask for help?” de Blasio said at a news briefing. “Do something rather than leave the bodies there. It’s unconscionable to me.” 

The mayor was responding to reports that the Andrew T. Cleckley Funeral Services in Brooklyn left corpses to decay in unrefrigerated U-Haul and other rental trucks on a crowded city street on Wednesday. When CNBC reached the funeral home for comment, a man who did not identify himself hung up before any questions could be asked. 

“I have no idea in the world how any funeral home could let this happen,” de Blasio said. “Absolutely unacceptable. Let’s be clear about this.”

New York City’s mortuaries, cemeteries, crematories and morgues have been overwhelmed by the volume of deceased coronavirus patients. The outbreak has killed almost five times as many New Yorkers in two months as the Sept. 11 terrorist attacks. 

Covid-19 has infected more than 164,000 people in New York City and killed at least 18,076 people, according to data compiled by Johns Hopkins University.

The situation at the Brooklyn funeral home was “aberrant,” de Blasio said, adding that most funeral homes across the city have done an “admirable job” in the midst of crisis. He added that there is a “substantial amount of refrigerated trucks available” to temporarily store corpses if funeral homes are overwhelmed. 

De Blasio said he supports a proposal by Brooklyn Borough President Eric Adams to form a “bereavement advisory group” to coordinate how the city’s private funeral homes can better care for the deceased.

New York Police Department spokeswoman Detective Denise Moroney confirmed to CNBC that officers responded to a call Wednesday about human bodies stored inside of two vehicles. 

The state Department of Health, which regulates all funeral homes in the state, has been notified and an investigation is ongoing, Moroney said. The state health department did not respond to CNBC’s request for comment.

Avery Cohen, a spokeswoman for New York City’s health department, said it is a “tremendously difficult time.” She said the city was ready to assist the state in ensuring local nursing homes could handle “this unprecedented crisis.”

The NYC Department of Health says it is convening weekly phone calls with funeral home directors to reiterate best practices and guidelines.

De Blasio said earlier this month the city was preparing to bury the bodies of those who died of Covid-19 in temporary plots on public land to alleviate the burden on overwhelmed morgues and cemeteries. The city has had to bury some people who died of Covid-19 on Hart Island, where more than 1 million people are buried in many unmarked and anonymous graves.

Last month, the Federal Emergency Management Agency said it was sending refrigerator trucks to New York City to serve as temporary mortuaries for deceased coronavirus patients. The agency said it has also deployed personnel to assist local medical examiners.