Dying chicks

[Athiena14]

I got chicks 4 days ago. 2 silkies and 2 unsure chicks. This morning 1 silkie and 1 other died for seemingly no reason. They other two have been loud most of the day. They have been in a large tub with 4 ducklings and 4 older chicks. They had been eating, drinking and pooping fine.
This evening the 2nd silkie was on it's back barely moving. I grabbed it and did the only thing I knew to do, try to give it some chick saver and put it and its sibling in the incubator to Hopefully get it warmed up, if that was the issue.
They have a heat lamp with the rest, but thinking the heat lamp was too low, I moved it up. They are in a large kiddie pool originally.

What could have happened?

 

[Shadowfire]

Can you post some pictures of the chicks, alive and deceased?

 

[Kiki]

How much older/bigger are the older ones?
Have you ever had to treat for Coccidiosis before?

 

[Athiena14]

I dont think the white one will survive the night...

 

[Athiena14]

How much older/bigger are the older ones?
Have you ever had to treat for Coccidiosis before?

They are 6 weeks. I've never had any have it before.

 

[Kiki]

What does their poop look like?

 

[Kiki]

They are 6 weeks. I've never had any have it before.

Are you sure these little ones have been able to eat and drink?

 

[Athiena14]

Are you sure these little ones have been able to eat and drink?

I've watched them eating and drinking

 

[Kiki]

Do you have Nutri-Drench on hand?

 

[Athiena14]

Do you have Nutri-Drench on hand?

Atm all I have is electrolytes for birds.