The City of Ottawa and the construction consortium chosen to build the city's light-rail transit line are facing a $100,000 lawsuit over the massive sinkhole that opened up on Rideau Street last June.

Starwood Capital Group Inc., which owns and operates the Westin Hotel in downtown Ottawa, alleges the city and Rideau Transit Group were negligent and failed to take necessary precautions at the LRT site during construction at the tunnel's entrance.

On orders from the Royal Canadian Mounted Police, the Westin had to evacuate the hotel on the morning of June 8, 2016 while it had a 98 per cent occupancy rate, the statement of claim alleged.

The evacuation order was lifted later that afternoon, but damage caused by the sinkhole led to the hotel having continued problems with its water and natural gas supplies for several days, according to the document, which was filed last week.

"Several banquets and catered events which were scheduled to take place at the hotel on June 8, 2016 were cancelled on account of the evacuation order as well as a number of room reservations which were cancelled or could not be fulfilled," the statement of claim alleged.

"Starwood was also required to incur significant out-of-pocket expenses to compensate its staff and customers for the inconvenience of the evacuation and issues with the hotel's utilities."

Site 'lacked adequate structural support and bracing,' lawsuit claims

Among the allegations against RTG are that the consortium should have known that the area where the sinkhole formed "lacked adequate structural support and bracing," yet it allowed those working conditions to persist.

None of the allegations in the statement of claim have been tested in court.

Though there were no reported injuries when Rideau Street collapsed, buses had passed over the road just minutes before the sinkhole formed. (CBC)

The sinkhole which grew into a 20-metre-wide gaping hole on Rideau Street and swallowed a parked van, forced other surrounding businesses to temporarily evacuate. There were no reported injuries.

In separate emails to CBC News, the City of Ottawa and RTG both said they do not comment on matters before the court.

Last April, a City of Ottawa report said instability of wet, sandy soil — not a watermain rupture — was the "highly likely" root cause of a massive sinkhole.

Engineering consultants McMillen Jacobs Associates wrote that installation of a pipe and excavating for a tunnel entrance had likely "disturbed and loosened" the ground.

The city report was not mentioned in the statement of claim.