Canadian Television is reporting that an overpass in a Montreal suburb remained open to traffic on Saturday, even though chunks of concrete were reportedly falling off of it about an hour before a whole section collapsed.

The collapse killed five people and seriously injured six others.

A provincial transport minister told CTV that just because a shoebox-sized piece of concrete falls off a bridge, that doesn’t necessarily mean the structure is about to collapse.

Former Quebec premier Pierre Marc Johnson will head a public inquiry into the cause of the collapse.

Meanwhile, inspectors will check 20 other similar overpasses to see if they have structural problems.