user: Question: What was the highest attendance when the result was L 6-28?
Columns: ['Date', 'Opponent', 'Location', 'Result', 'Attendance']
Types: ['text', 'text', 'text', 'text', 'real']
Sample row: ['09/09/1978*', 'Virginia', 'Groves Stadium • Winston-Salem, NC', 'W 14-0', 21500.0]
SQL:

assistant: SELECT MAX("Attendance") FROM "Table" WHERE "Result" = 'L 6-28';