Sheppard-Yonge Station was evacuated for about an hour Sunday after a hydro vault fire sent smoke wafting through track level.

Emergency responders were called to the station at around 3:30 p.m. after grey smoke was seen coming through the grills. People in the station also reported hearing a loud noise.

Toronto Fire said crews arrived to see smoke visible at a construction site near the station and they traced the source to a hydro vault fire.

Toronto Fire said five TTC staff were being assessed at the scene for minor smoke inhalation.

Toronto Fire cleared the scene at around 4:45 p.m.

Subway service bypassed Sheppard-Yonge station on lines 1 and 4 for about an hour but has since resumed, the TTC says.