The Singapore Airlines flight that hit turbulence and left one person dead dropped around 178 feet in 4.6 seconds, according to data extracted in early investigations.

The London-Singapore flight encountered the turbulence over Myanmar and had to make an emergency landing in Thailand.

BBC News says a preliminary report by investigators said rapid changes in gravitational force caused the altitude drop and likely injured those who were not wearing seatbelts.

One British passenger, 73-year-old Geoff Kitchen, died from a suspected heart attack onboard.

The drop in altitude is said to be just shy of the height of Italy’s Leaning Tower of Pisa.