Toronto transit riders are shaken today as news spreads of a man who was pushed to his death in front of a subway train at Bloor-Yonge Station by someone he didn't know.

Police have charged a 57-year-old man with first-degree murder in connection with the incident, which took place on an eastbound platform around 10:15 a.m., and are still working to identify the victim.

The deceased is described as an Asian man with white hair in his 50s or early 60s. Police say he had no connection to the suspect, and that the two men interacted only briefly, if at all, before the victim was pushed and struck by an approaching train.

It's time we invest in barriers :(

“Death of man struck by Toronto subway being investigated as a homicide”https://t.co/mWoAFEcffm

— Queen B (@iMedOli) June 19, 2018

A case like this is "incredibly rare on the TTC," according to transit officials.

The last person killed in such a manner was 23-year-old Charlene Minkowski in 1997, according to The Star. Archived news stories say that she was pushed from the platform at Dundas Station by a "disturbed" man with schizophrenia.

Three teen boys were similarly pushed at Dufferin Station in 2009. All survived but two needed to have toes amputated. The person who pushed them is said to have had a mental disorder and was thus found not criminally responsible.

Calling this week's death "tragic," the TTC says that it will learn from the incident and plans to "review any measures that could further reduce the chances of it happening again."

Platform screen doors — the kind used to prevent suicide by subways in Tokyo, Paris, Bangkok, Beijing, Hong Kong and other cities — could be one such measure, as hundreds around the city are now pointing out (and not for the first time).

So Subway Platform Barriers come in all shapes, sizes and costs. You can even install video ad panels on them to defray costs. The panels could even include interactive wayfinding terminals. This is not that hard. @NEWSTALK1010 @MooreintheAM @joemihevc #TOpoli #TTC pic.twitter.com/uubfWELsas

— Shelley Carroll (@shelleycarroll) June 19, 2018

Deaths by suicide are indeed a problem for Toronto's subway system, and these deaths are seldom talked about in news reports (in accordance with the city's suicide prevention strategy.)

A total of 45 people attempted suicide on the TTC last year alone. Nineteen of them died, according to TTC spokesperson Brad Ross.

Concerned riders have been calling for platform barrier doors for years, and this most-recent pushing incident has dramatically intensified the discussion.

Toronto: OMG #BellLetsTalk ! It's okay to not be okay! We are here 4 u!
Mentally Ill Torontonians: Well, a thing that would really help is subway platform barriers-
Toronto: LIFE ISN'T ABOUT WEATHERING THE STORM; IT'S ABOUT LEARNING TO DANCE IN THE RAIN! RIP ROBIN WILLIAMS!

— Absolute Unit (@ChurchCarlton) June 19, 2018

Ross responded to one Twitter user's question yesterday about why the doors haven't been installed yet, writing that an engineering study is actually underway.

"Once complete, estimated costing to be done, then funding," he said of the study. "Doors are going to cost at least $1 billion."

It's hard when to say the doors will actually be installed, however, should the study even greenlight them in the end. 

TTC officials recommended the same move back in 2010, saying at the time that they hoped to install suicide barriers on at least some subway platforms "within three or four years."

"The first phase, from Eglinton to Union, won’t be complete until 2013," wrote The Star at the time. "And it will be 2015 before it is installed all the way to Downsview."