Horrific photos showing the remains of the stretch limo involved in last year’s deadly upstate crash that killed 20 people were released Wednesday — as investigators said some of the passengers may have survived if they’d been wearing seat belts.

The never-before-seen photos revealed in the National Transportation Safety Board’s safety recommendation report showed the totally destroyed and crumpled front of the white stretch limo, a customized 2001 Ford Excursion, in the aftermath of the Oct. 6 wreck in Schoharie.

That tragic afternoon, the limo, driven by 53-year-old Scott Lisinicchia, sped through a stop sign at a T-intersection in the rural town and barreled into a small ravine, killing the driver, all 17 passengers inside, including four sisters and three of their husbands, as well as two bystanders.

The NTSB wrote in its report that despite the severe damage to the vehicle — operated by Prestige Limousine and previously modified into a stretch limo — “rear portions of the passenger compartment remained relatively intact,” so some of those in the back could have lived if the vehicle had more readily available seatbelts and if those inside had been wearing them.

“Because survival space was maintained in a portion of the passenger compartment and the passengers may have had an opportunity to ride-down the crash forces … injuries to occupants within the passenger compartment might have been mitigated by a combination of adequate seat integrity, well-designed passenger lap/shoulder belts, and proper seat belt use,” the NTSB wrote in the 15-page report.

“These were not available in the crash limousine,” the report said.

Evidence indicated that none of the passengers were wearing seat belts at the time, the report said.

Regardless, the passenger belts in the limo weren’t the original ones that came with the car, “were not properly designed for occupant crash protection” and were “under the bench seats and invisible to passengers.”

Lisinicchia was wearing his seatbelt at the time of the crash and the airbag in the vehicle deployed, but “the “crash was not survivable” for him, the report said.

In the days after the wreck – which was the deadliest US crash in a decade – it was revealed that the driver and limo should have never been on the road as he wasn’t properly licensed and the vehicle had failed a state safety inspection a month earlier.

The limo company’s operator, 29-year-old Nauman Hussain, has been charged with criminally negligent homicide and manslaughter in the case.

The NTSB report does not say what caused the wreck, but notesthat the probable cause will be established in its final accident report once it wraps up the investigation.

Meanwhile, the report calls for new national requirements for seating and seat belt systems on limousines.

The agency recommended that the National Highway Traffic Safety Administration require lap and shoulder belts for each passenger seating position on all new vehicles modified to be used as limousines.

It also recommended that seating systems in these vehicles meet minimum performance standards “to ensure their integrity during a crash.”

The NTSB called on the National Limousine Association to educate members on the benefits of proper seat belt use and recommended that the state Department of Transportation ensure all limousine belts are functional and accessible in its regular inspection process.

Currently in New York, limousines are not required to have seat belts for the rear passengers.

The state Senate passed a series of bills in June aimed at preventing fatal limo crashes like the one in Schoharie. Out of the nine bills passed, only one also made it through the state Assembly.

A bill that would require seat belts in any altered vehicle transporting nine or more passengers has only passed the Senate.

Following the release of the NTSB report, state Department of Transportation Commissioner Marie Therese Dominguez said the NTSB’s recommendation that the state “incorporate the inspection of seatbelts for functionality and accessibility into [the agency’s] biannual vehicle inspection process” is “something that in fact has been standard protocol in our process since the early 1990s and are incorporated into the Code of Rules and Regulations for New York State.”