Qantas has sent emails to customers affected or potentially affected by a cyber attack, but none of its executives have yet fronted the media.

Australian airline Qantas says a data hack on Monday exposed the personal information of six million customers and it expects the amount stolen to be “significant.”

Qantas, the flag carrier of Australia, announced this week it was the target of a cyberattack that compromised data belonging to 6 million customers. The airline said it is still investigating the full extent of the data breach,