Service through the Bay Street tunnel has not resumed, as the TTC is bringing in a contractor to grind away at the concrete floor at certain locations so that the tracks can be reinforced. 511 Bathurst cars, already barred from Fleet Street, are turning around at Queens Quay and Spadina. Now a reader tells me that streetcars are being diverted around the Spadina Avenue bridge over the railroad tracks, so that emergency track repairs can take place. 510 Spadina streetcars are operating via Spadina, King, Bathurst and Queens Quay to loop at Queens Quay and Spadina. Service will not return until the work is complete and inspected. Shuttle buses are providing service along the length of the 509 Harbourfront route.

TTC patrons have noted that no announcement of this ongoing service disruption has been made on the TTC website.

(Update: Tuesday, 8:09): Service on Spadina south of King has resumed.

(Update: Tuesday, 11:24 a.m.): TTC Information reports that the diversion is continuing.

(Update: Tuesday, 11:58 a.m.): Steve Munro spoke to Jim Teeple at the TTC and finally gets us some hard facts:

contrary to some reports, the problem is not in the tunnel, and it is at Rees Street as previously reported.

There is a problem with the track sinking for reasons they don’t yet understand, and the effect is that the track brake drags on the concrete (that’s why they want to grind some of it off). If the track brakes get badly hung up, this could cause a derailment.

The delay in activity is caused by the fact that the TTC wants to dig to see what is happening under the trackbed, but cannot do this until the utility companies come and mark where their services are. Apparently they are taking their time about it.

(Update: Thursday, 5:06 a.m.): A reader reports that service through the tunnel has resumed — perhaps as early as Tuesday morning — although the TTC information line continues to report that streetcars are diverting.