An Air India pilot turned back his Delhi-bound Boeing 787-8 Dreamliner to Hong Kong airport as a precaution shortly after taking off on Monday, citing a technical issue, Indian media reported. Flight tracking data showed the pilot turning Flight AI315 around less than 30 minutes into the flight from Hong Kong.

At least 270 died when the Air India flight crashed into the campus of a medical college in Ahmedabad shortly after takeoff on Thursday.

Boeing shares fell more than 4% in afternoon trading.