A long-abandoned stable at the Blue Bonnets site caught fire Saturday night.
Firefighters received the first call around 6:30 p.m. and found that stable #9 was in flames.
The stables are some of the last buildings standing on the southern extremity of the site, close to the border of Cote-Saint-Luc and Hampstead.
It reportedly took over an hour to control the fire.
Montreal police were temporarily on-site, but ultimately didn't launch a criminal investigation.
The fire is believed to have started accidentally, although the exact cause is unclear.
No one was injured.
The Hippodrome closed in 2009 after 137 years in operation.
The remaining buildings were abandoned and vandalized over the years.
