user: Question: What is the Badge/Serial Number of the Policeman who died in Gunfire on 1919-02-18?
Columns: ['Rank', 'Badge/Serial Number', 'Tenure', 'Date of death', 'Cause of death']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['City Marshal', '—', '—', '1853', 'Gunfire']
SQL:

assistant: SELECT "Badge/Serial Number" FROM "Table" WHERE "Rank" = 'Policeman' AND "Cause of death" = 'Gunfire' AND "Date of death" = '1919-02-18';