Band aids are treatment, not a prevention by purpose. So yes, while you'll never achieve perfection, you can reduce ill effects.
How many of those tweets talk of retaliation etc.? How are you supposed to prevent retaliation. We you never will prevent all retaliation but you can try.
For example, the City has a program called Youth Outreach Workers who are young mentors hired from the communities themselves. They are uniquely positioned exactly in communities like this to know what the situation is on the ground, and have the established relationships within those involved in acts like this. They mobilize in situations like this to do what they can to prevent retaliation. They know who to speak to, and how to talk them down. They can do that because they are trusted members of these communities themselves because they have been there for years and came in with an aim to mentor. These workers are also sometimes the link between the community and police. Their success is immeasurable because you can't really measure when one of them talks down a gang-involved person looking for revenge. But they work. They mobilized after the Eaton Centre shooting and they will mobilize in this crisis to try to prevent retaliation. It's worth mentioning the city was looking to chop over half of them in the last round of Rob Ford's budget cuts. Luckily they were saved by Council a few months ago.
That's just one example where a complex situation exists, and requires a bit of complex thinking with the solution.
A lot of these communities suffer from isolation resulting from bad planning in the 50's. If you were born in a community where nothing changes and its difficult to get out of physically (relatively speaking), it can contribute to any socio-economic mire it finds itself in. We do know that Canada is not sheltered from the widening income gap. This is especially pronounced in Toronto's suburbs where the middle class of yester year has virtually vanished.
Worth Reading:
Tackling the income gap in Canadian cities - thestar.com
Transit initiatives such as the LRT to Scarborough can help reduce feelings of isolation and connect it to the rest of the city. These tower-heavy communities may become re-animated through wider public transit accessibility.
Just a few points to describe how some initiatives that go beyond 'installing a basketball net' can help reduce problems over time.
The Priority Neighbourhood Program and
Priority Centres,
Welcome Policy etc are some other City initiatives that assist lower-income communities with programs.
Sometimes we aren't comfortable with solutions that take a lot of time, and dedicated funding but really those are the only things within Toronto's power beyond policing (treatment) to legitimately reduce violence, poverty, unemployment.