iPhones now comes with a feature,
which keeps you safe in a unfortunate event of a car crash.
But this feature got confused,
while understanding a condition.
Many people from US has reported that this feature
detects roller-coaster ride as some car crash.
When iPhone detects there has been car crash,
it displays a alert and initiates a emergency phone call
after 20 seconds unless you cancel it.
So while on roller-coaster ride if the phone user is unable to cancel the emergency call.
It will lead to dial unnecessary calls to emergency number while on roller-coaster.
As of now the suitable solution for this problem is,
to keep your iPhone on Airplane mode or switch it off while on rollercoaster ride.
Apple may improve their crash detection over time.