The Virtual Worlds Forum has been cancelled less than 24 hours before the event, due to a shooting at the venue.
Police have closed The Bridge in London for three days, leaving the organisers no option but to postpone the event, scheduled for today and tomorrow (October 6-7).
"With less than a day to go, we cannot find an alternative venue, so we have taken the very difficult decision to reschedule the event," said a representative.
Some scheduled networking opportunities are still taking place, including the South by South West party tonight and access to the Hospital venue for those with a pass.
This year's Virtual Worlds Forum was due to feature keynotes from Mel Guymon of Google Lively, EA's John Burns, Gaia Online's CEO Craig Sherman and Jagex's Geoff Iddison.