The ramp from the eastbound Highway 401 collector lanes to northbound Highway 427 has been closed for emergency repairs.
The ramp was previously reduced to one lane due to ongoing construction, but was shut down unexpectedly Tuesday morning.
Ministry of Transport officials told CTVNews.ca that private contractors working on the ramp Monday afternoon noticed the bridge deck had shifted.
Structural engineers later evaluated the ramp and closed it as a precautionary measure. MTO officials confirmed the ramp will likely remain closed until 6 a.m. Thursday, but hope to have it open before then.
Signs on the 401 are alerting drivers of the closure, and first responders have also been advised.
