Air India Express 171's crash report offered no closure - just more speculation and one haunting, unexplained detail.

Air India said on Tuesday it has completed precautionary inspections of the fuel control switch locking mechanism on all its Boeing 787 and 737 aircraft, with no issues detected. The probe into the Air India crash that killed 241 of the 242 people on board and 19 on the ground is focused on the fuel control switches of the Boeing 787 jetliner,

With 260 casualties and only one surviving passenger, the Air India 171 crash is one of the deadliest aviation incidents in recent history — and so far it’s proving to be one of the most frustratingly opaque.