I'm heartbroken about the horrible, vile, criminal act that was perpetrated upon Kyoto Animation on the 18th of July. Kyoto Animation has long been a shining light in the industry, producing works full of joy and humanity and always putting the well-being of their staff above everything else. My heart and thoughts go out to all of those affected by the horrible incident, both fans of KyoAni but above all else the family, friends and colleagues of those who were killed and hurt.

It is hard to know what we can do to support them at this time, but if you have the ability please consider buying something from their digital store. My understanding is that all the proceeds go directly to Kyoto Animation itself:
Kyoto Animation Digital Shop

Update
Since I first write this, more options to support Kyoto Animation have become available.

The best one is to donate money directly to the bank account that KyoAni set up for the purpose:
http://www.kyotoanimation.co.jp/information/?id=3075

The post also include links to other ways to donate and support the victims of the tragedy and the rebuilding of the studio itself.