A haunting simulation video is shedding light on possible reasons behind the tragic Air India Flight 171 crash that killed 270 people. The Boeing 787-8 went down just seconds after taking off from Ahmedabad, crashing into a hostel block and leaving only one survivor, 40-year-old Vishwash Kumar Ramesh.

Officials found the black box, which India’s Aircraft Accident Investigation Bureau says will be key to uncovering what went wrong. Early reports say the plane climbed to 625 feet before losing power. The pilot’s final mayday call revealed: “No thrust, losing power, unable to lift.”

Experts and the AiTelly video suggest possible causes include a fuel system issue or mechanical failure in both engines, since no smoke or sparks were seen. Some believe a flap or landing gear error might have caused the jet to lose lift too soon.

Commercial pilot Captain Steve believes human error is possible. He thinks the co-pilot may have raised the flaps instead of the landing gear: “If that happened — and it’s a big if — it explains why the airplane stopped flying.” Investigations are still underway.