Emergency crews on still on the scene of an active fire at Pioneer Flower Farms in St. Catharines.
St. Catharines Fire was first on scene shortly after 11 p.m. at 1900 Seventh Street Louth, south of Third Avenue.
Over 30 units have responded including detachments from Thorold, Lincoln and Niagara-on-the-Lake.
Acting fire chief Jeff McCormick says things have been made more difficult after the first building engulfed in flames collapsed, blocking the fire route.
That has made it difficult for fire crews to access the whole compound.
Another concern is the fire spreading to the brush behind the property.
The east-side of the greenhouse has lots of adjacent brush, and crews are preemptively soaking the area to contain the spread.
Emergency personnel are asking you to please avoid the area.
Residents nearby are being urged to stay indoors, close their windows and turn the air-conditioning off.