A fire investigation shut down service on the TTC's busy Line 1 subway between Sheppard-Yonge and Finch stations temporarily this afternoon.

Line 1 Yonge-University: Regular service has resumed between Sheppard-Yonge and Finch. https://t.co/DihyYtdYMQ

— TTC Service Alerts (@TTCnotices) January 15, 2020

Someone captured a video of small flame on the tracks at Finch Station, just before a train rolled in.

Someone captured flames on the subway tracks at Finch station. Service was temporarily closed between Sheppard-Yonge and Finch for a fire investigation - 📹 @alisasavina #Toronto #TTC #Fire pic.twitter.com/MjFXdiU5Uk

— blogTO (@blogTO) January 15, 2020

Smoke could be seen billowing out of the subway tunnel while TTC users waited on the platform.

JUST IN: @TTCnotices say there is no service between Sheppard-Yonge and Finch because of a Toronto Fire investigation. Shuttle buses are being called in. This is what it looked like, moments ago: pic.twitter.com/BJh9VWlRpR

— NEWSTALK1010 (@NEWSTALK1010) January 15, 2020

Shuttle buses were sent to the station, but the issue was resolved after about 30 minutes.