A hydro vault fire has shut down one of Toronto's most-travelled subway routes for more than two hours now – and it won't be up and running for some time yet.

TTC officials announced shortly after noon on Tuesday that service had been suspended on Line 1 from Spadina to Union Station for a fire investigation at Queen's Park.

Fun Toronto fact: At least a small part of the TTC is always one fire

— ugh (@baylyh) January 16, 2018

Trains started turning back at both Union and Spadina stations at that point due to what the TTC described as a "hydro vault fire" at University and College.

Even mid-day, when ridership on the subway is typically much lower than what we see during mornings, afternoons and evenings, passengers are lighting up Twitter with complaints about delays.

As usual, the @TTC finds new ways to frustrate and disappoint. It's not close to rush hour and Spadina station is a shitshow.

— Shannon Parks (@shannyp416) January 16, 2018

It's been a rough day overall for the TTC, and largely through no fault of its own. 

Service was suspended both ways at Warden Station earlier this morning due to a trespasser at track level, followed by a fire investigation at Jane Station, a medical emergency on a train near Summerhill Station and now the 512 St. Clair streetcar is turning back at St Clair West Station because of a collision.

Got stuck in this & now I'm sitting not moving on Line 2 westbound at High Park. What's going on with the TTC today? https://t.co/yTLEStp7Fv

— Dan Levy (@TheDanLevy) January 16, 2018

Subway service between Spadina and Union will be suspended "until at least 4 p.m.," according to City Councillor Michael Thompson. 

"Be sure to plan an alternate route," he suggests – especially heading into the afternoon rush hour, which could very well see a crush of commuters stopped up by a still suspended line. 

#TTC is currently flying at half mast @TTCwelps #TOpoli pic.twitter.com/xHCF9mcCDr

— Norman Di Pasquale (@normsworld) January 16, 2018

In the meantime, TTC customers can hop aboard shuttle busses, hail cabs, call their moms, cry on Twitter, or walk a few blocks over to access stations on the adjacent Yonge Line.

Update: TTC officials announced just before 4 p.m. that the delay at Queens Park had been cleared and that subway service has now resumed on Line 1.