A wayward eastern grey squirrel may be to blame for a power surge Wednesday morning that caused traffic tie-ups in Toronto's downtown core and left parts of the financial district powerless.

"Sometimes if a squirrel comes into contact with our equipment it could become electrocuted and cause a short in the system," said Toronto Hydro spokesperson Tanya Bruckmueller.

"Generally animals play a large part in outages outside of the downtown area, but they do cause problems on our [downtown] system." 

The area between Yonge Street and Spadina Avenue and from Queen Street south to the lake was hit by the power surge around 11 a.m.
   
Many businesses in the financial district were affected by the outage. Traffic lights were also affected, leading to major slow downs in the city centre.

It took hydro crews about two hours to get service back to normal.