Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_17257687_1 (air_date VARCHAR, event_1 VARCHAR)
### Question:
On how many different dates was event 1 Suspension Bridge?
### Answer:
SELECT COUNT(air_date) FROM table_17257687_1 WHERE event_1 = "Suspension Bridge"