From Apple Daily HK. Basically the flight took off from JFJK and hours later they found out they ran out of water and has to divert to YYZ. They need to switch to another aircraft and the flight was delayed for 22 hours. The experts believe this is probably caused by maintenance oversight because if they forgot to refill the water tanks, they didn't have to switch the aircraft. Edit: Sorry my bad. Diverted to YYZ not YZZ as stated in the title.