The City of Ottawa says a hole that formed on Rideau Street Thursday likely happened after soil beneath the surface settled, creating a pocket that weakened the road.

The two-metre wide and metre deep hole formed sometime after 1 p.m. in front of the Hudson's Bay store, just east of Sussex Drive, over a sanitary sewer.

Buses have been removed from Rideau Street as crews assess the hole. (Stu Mills/CBC)

Rideau Street has been blocked to traffic as a precaution and as of 9:30 p.m. Thursday had yet to reopen.

City workers have backfilled the hole with concrete and installed a steel plate over the area. Once an engineer signs off on the repair, the street will reopen, said Steve Cripps, the director of O-Train construction wrote in a statement.

Cripps said it appeared when crews looked inside the hole that there was "some settlement of material" — that city staff later confirmed was soil — that left a small void "which allowed material from above to shift slightly downward causing the pothole at the surface."

OC Transpo has temporarily removed its buses from Rideau Street.

Routes 4, 5, 6, 7, 9, 12, 14 and 18 will now pick up passengers on the Mackenzie King Bridge "until further notice," OC Transpo said.

Repair work done

City workers backfilled a hole that formed on Rideau Street Thursday, Nov. 2 and installed a steel plate over it. (Michel Aspirot/CBC)

Rideau Street was the site of a massive sinkhole in June 2016 that caused a gas leak, forced the evacuation of nearby businesses, and affected traffic for months.

A city report pinpointed the likely cause of the sinkhole as unstable soil brought about by work on a nearby light rail tunnel.

The hole that opened up Thursday afternoon is east of the location of the 2016 sinkhole, Cripps wrote in an email, and is "totally unrelated to the earlier event."