A Thornhill house fire Friday led police to an indoor marijuana growing operation.

Firefighters found the basement and attic of the home, in the area of Clark and Henderson avenues, engulfed in flames when they arrived. As they worked to douse the blaze, which was threatening neighbouring properties, they saw the grow op and called police.

During a search, police seized 60 marijuana plants and electrical equipment. The Ontario Fire Marshal later determined the fire was caused by wiring and fixtures related to the grow op.

Hung Truong, 39, of Markham is charged with arson endangering life and production of a controlled substance.

If you have information, call police at 1-866-876-5423, ext. 7066, Crime Stoppers at 1-800-222-TIPS or leave a tip at www.1800222tips.com