A 4-year-old boy has died after he never woke up from a nap at a preschool in Jersey City.

Staff at the Cordero School found the boy unresponsive Thursday after he took an afternoon nap.

The boy was rushed to a hospital, where he was pronounced dead.

Parents near the school tell News 12 New Jersey they are concerned.

"I'd be curious to know what the situation is. Is there a health issue? Is there some kind of safety issue that we should be aware of as a parent? As a community person? As a taxpayer? I'd like to know more," asked mother Sandi Oyola-Pike.

Principal Derek Stanton said in letter to parents they will have grief counselors at the school today.

The boy's name has not been released.

There is no indication of foul play.