 often caused by technical errors, cyber attacks. The scale of what unfolded Friday has been unparalleled. It's historic, said the chief research officer at Wits Secure, a cybersecurity company. We haven't had an incident like this. The problems apparently cascaded instantly. In Sydney, Australia, travelers encountered delays, cancellations. The same thing happening in Hong Kong, India, Dubai, Berlin, Amsterdam. At least five U.S. airlines canceled