In addition to "switched to the news", "flipped(over) to the news" can be used idiomatically here, although I think it is slightly informal (and relatively rare, see edit).
"Zap" is also apparently a word of the meaning you're looking for, as stated in other answers, but I haven't heard it used in everyday speech.
In addition to that, because, in this case, the television has only just been turned on, I think saying "put/switched on the news" would also work, without making reference to the channel being changed.
Edit: As per one of the comments on this answer, it appears that "flipped over" is very rarely used in writing (which is what you're looking for); I based this off what I have heard used in everyday speech, and this also comes with the caveat that it may be more specific to the UK, or maybe even the Midlands. I also note that "flicked" is also used in this way, but with similarly low frequency. "Switched" appears to be the more common term at any rate.