By David Reevely, Ottawa Citizen, December 22, 2016
No failure by the city government was to blame for last June’s massive sinkhole on Rideau Street, city solicitor Rick O’Connor reported Thursday, but experts aren’t sure why it happened and the public can’t see their report.
The sinkhole was “a complex event,” O’Connor wrote in a memo to city council. And right after it happened, contractors began pouring 3,000 cubic metres of concrete into the pit by the Rideau Centre just east of Sussex Drive, which made investigating the cause challenging.
http://ottawacitizen.com/news/local-news/it-wasnt-us-city-says-of-the-rideau-street-sinkhole