Ticket sales for the Games were halted after demand proved to be far too much for the database to handle. The ticketing database could supposedly process 150,000 transactions an hour, but in just the first hour, the Games' site had 8 million hits, its hotline had 3.8 million calls, and 200,000 orders were taken from customers.
Originally, the Olympics organizers had planned to sell tickets in three phases. Of the 7 million tickets available, 1.6 million were allocated in the first phase, through a lottery earlier in the year. The second phase - which was intended to be a first-come, first-served sale - unfortunately only amounted to 43,000 tickets (of 1.85 million available) being recorded as purchased before the system failed, leaving the outstanding orders unfulfilled.
Because of the crash, a new system will have to be put into place. That system won't be available until 11/5.