All lanes are now open on Bathurst Street under the Gardiner, after yet another instance of falling concrete.
However, engineers at the scene say this incident differs from previous incidents.
The oppressive heat over the last few days, has caused swelling of the rebar underneath the concrete, leading to the breakage.
Crews working to chip away at the expressway's belly say it's a much more difficult task, because the concrete is in fairly good condition.
A complete rehab of the elevated part of the Gardiner is set to begin in a matter of days.