Baby chicks dying all of a sudden

[crazypolishchic]

We have 7 one month old baby chicks we incubated and hatched that were fine a few hours ago but all of a sudden started dying. 3 are dead already and 1 is breathing heavily. There haven't been any noticeable symptoms of them being sick until about 30 minutes ago when my husband noticed they didn't sound right.
They are in an indoor enclosure but I have taken them out the last couple of days to forage in the grass and get used to outside. We haven't done anything different except clean a coffee pot with vinegar in the vicinity & start a new bag of medicated chick starter this morning.
Help! Don't know what to do.

 

[Polishpal]

I actually had thiis problem too, I bough some electrolytes and that helped my 2 survivers live. But I don't know what to say but this happens to me when I use incubators. That's why I let my hens take all the burden of the little peepers.

 

[missnu01]

If they are breathing hard is it possible they are too hot under whatever light you are brooding them with? My chicks are 4 weeks and we've been turning the light off during the day and on low at night...most houses are warm enough right now to not need extra heat during the day... If we have our woodstove going then we leave the lights off at night too. They only need it at most 70 degrees. I'm not saying anything over 70 will hurt them, but if your house is 70 and you have a heat lamp on them they are probably overheated...
And did anything about the new bag of feed seem off? Weird smell? Anything like that?
Also have you given any chick grit? You said you had them outside..does your soil have sufficient smaller rocks to serve as grit so the grass they eat will be ground into food as opposed to staying a crop choking mass of grass? Those are my best guesses