SCHEMA:
CREATE TABLE table_name_15 (year INTEGER, death_toll VARCHAR, cause VARCHAR, colliery VARCHAR)
USER:
Count the lowest Year which has gas explosion, Colliery of tylorstown colliery, and a Death toll larger than 57?

QUERY:
SELECT MIN(year) FROM table_name_15 WHERE cause = "gas explosion" AND colliery = "tylorstown colliery" AND death_toll > 57