They just took their website down:
Dear Valued Customer,
We regret that our website is temporarily unavailable.
This is because Singapore Airlines and SilkAir are currently undergoing a transition to a new reservations system at this time.
As such, bookings through
www.singaporeair.com,
www.silkair.com, call centres, service centres and travel agents are not available. All KrisFlyer-related transactions, as well as online/mobile functions (e.g.SMS alerts, etc) are also suspended. We expect to resume these services progressively from 2200 hours on 08 July 2012 Singapore local time (GMT+8).
During this period, all our flights are due to operate as scheduled. However, please note that Internet, mobile and early check-in is not available for all flights on 08 and 09 July 2012 Singapore local time (GMT +8). For information on flight status, please check with the respective airports.
Should you require urgent assistance, please email us at
[email protected]. For non-urgent service or general feedback, we would appreciate if you could visit our website after 2200 hours on 08 July 2012 Singapore local time (GMT +8).