There isn't much left now. A thin column of floors and part of the building's brick exterior, framed by piles of rubble, are all that remain of the old St. Catharines hospital on Queenston Street.

It won't be long until a wrecking crew topples what remains.

What cannot be seen at street level are a series of chambers, tunnels and basements — architectural leftovers from the hospital's past — that reside underground.

"We've even found a swimming pool underground, that was in the back of one of the buildings," said Mike Starnino, with Starnino Environmental Recovery Inc., the firm doing the demolition on the decommissioned hospital site.

"There are old tunnels, one of them looks like it connected to a church. Another one looks like it goes under Queenston Street, but looks to be bricked over. There are old steam tunnels that used to carry water. These are things we are finding as the demolition goes forward."

What lies beneath is more than just a historical footprint of an old hospital. It presents a potential hazard to Starnino's crews and, he said, explains why the demolition has happened at a measured pace.

Some of these underground structures aren't on any drawings or maps. So before any piece of the old building is demolished, Starnino's teams hamust excavate the area first to determine what might be lurking beneath.

"You have to be careful. If the concrete is rotting or area is unstable it could be hazardous," Starnino said. "If you have a guy 100 feet up in the air (in a wrecking machine) and the ground collapses, that would be really serious."

The Starnino Environmental teams have to assess what is under their feet and shore up anything that could give way so they can continue the teardown process.

"What is why the demolition is taking as long as it is," Starnino said. "You have to go the extra mile for safety."

The hospital opened on Queenston Street in 1870 and was closed in 2013 when the hospital on Fourth Avenue opened its doors. Apartment buildings are expected to be built on the land once demolition and cleanup is completed.

A historic, ornate entrance to the hospital has been left standing amid the rubble of the demolition. property developer Michael Corrado, who could not be immediately reached for comment for this story, has said he intends to incorporate it into the new buildings.

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