An Emirates A380 from Los Angeles (LAX) to Dubai (DXB) has been diverted twice, initially due to a medical emergency on board. 

Flight EK216 declared emergency over the Hudson Bay and diverted to Toronto (YYZ), reportedly because of a sick passenger. 

Rather than continuing to Dubai, the super jumbo is now flying to London, flight tracker FlightRadar24 shows. This is likely because the crew will be over duty hours if they try to press on to Dubai. 

Medical emergencies are more common than you might think onboard aircraft. Back in 2015, a medical journal estimated there were around 1 in every 600 flights, equivalent to an average of 50 a day in the United States alone.