Air India's deadly plane crash that killed at least 270 people has triggered a wave of speculation about what led to the world's worst aviation disaster in a decade, but authorities are slowly narrowing down areas of investigation.

A helicopter crashed in the northern Indian state of Uttarakhand on Sunday, killing seven people on board. Local officials said the aircraft was flying from the town of Kedarnath to Guptkashi, which is a prominent Hindu pilgrimage site in the Himalayas.

A tragic helicopter crash near Kedarnath in Uttarakhand has claimed the lives of seven people, including two children. The incident occurred early in the morning around 5:00 AM when a helicopter carrying pilgrims from Kedarnath temple to Gaurikund lost control and crashed near a hilly area close to Gaurikund.