Authorities are investigating one of India’s worst aviation disasters a day after an Air India plane crashed, killing all but one of the 242 passengers and crew onboard, officials said Friday, as Prime Minister Narendra Modi visited the crash site.

Prime Minister Narendra Modi said he was “devastated” after visiting the site of Thursday’s plane crash in western India, where more than 240 people were killed.

All but one of the 242 people on board the London-bound flight died when it crashed into a residential area in Ahmedabad shortly after take-off.