Singapore Airlines has tweaked its in-flight seatbelt sign policies and altered at least one flight route after a turbulence incident this week killed one person and left dozens more hospitalised, according to the airline and flight data.<br /><br />WATCH MORE: https://thestartv.com/c/news<br />SUBSCRIBE: https://cutt.ly/TheStar<br />LIKE: https://fb.com/TheStarOnline
