user: Question: What event has Unknown as the days held.?
Columns: ['Wrestler', 'Reign', 'Days held', 'Location', 'Event']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Filoso', '1', 'Unknown', 'N/A', 'Live event']
SQL:

assistant: SELECT "Event" FROM "Table" WHERE "Days held" = 'Unknown';