Why are so many babies being forgotten in cars and dying?

R' Chaim Kanievsky is reported as answering as follows:

הסיבה לצרה כזו, היות ויש בשנים האחרונות הרבה פושעים ביננו, לכן באה כזה צרה לעורר אותנו לבער את הרע מקרבנו, ולשוב אל ה

The reason for these tragedies is that since in the last few years we have so many sinners among us these tragedies are coming to wake us up tid ourselves of the evil within the community and to return to Hashem

Really??? God is killing innocent babies so that the we should rid the community of sinners? Why not just kill the sinners? 

It is beyond me how anyone can think that they know why an omniscient and omnipotent God is doing anything.

Source: http://www.kikar.co.il/211629.html