It takes quite a while for a baby to exit the egg, sometimes up to a day or two.  It will use the egg tooth to begin the process by cracking the shell.  The pictures above show the sequences of the hatching.  You can imagine how tired this little one will be by the time it is completely out of the shell. 

The egg tooth will disappear in a few weeks.  The yolk sac will continue to give nutrition to the baby.  In a few weeks, it will be interested in eating live food such as small worms, bee moths, meal worms and bugs.  As they get older, they will be more interested in fruits and vegetables. 

This photo shows a 6 month old, a one year old and a 2 year old box turtle. 

At Indiana Turtle Care, baby turtles are measured and weighed every 6 months.  Each turtle has a record sheet where information is available to compare proper growth rate. 

Hatchlings should be kept in an environment that supplies the same requirements that they will need as an adult, with a few exceptions.  They require more humidity and the importance of a UVB light cannot be stressed enough.  UVB lights are necessary for proper growth.  You will not need a large pen for hatchlings.  I personally use small plastic storage containers.  They are portable, inexpensive and easy to clean.  For substrate, several materials can be used, such as sterile potting soil, mulched leaves, and cypress mulch, making sure it is damp.  Hatchlings like to bury and hide.  To allow this, the substrate can be deep enough for this or you can add flower pot laid on its side.   For a water dish, a small plastic planter saucer is ideal  for easy access.  They will eat live food such as meal worms, crickets, redworms, and bee moths, all small size.  You can help with this by cutting them in small pieces.  A heat source should also be supplied, having the temperature in the high 70's or so.  The heat and UVB light can be turned off at night, to simulate a day-night cycle.  If the hatchling does not use the water dish, it is important to soak it every other day in warm water.  Hatchlings can easily dehydrate.

During the warmer months, they stay outside in secure lidded pens.  There is also wire flooring to keep the in the pen in case they decide to dig. 

Unfortunately, some eggs hatch prematurely.  As you can see in the photo below, this little one's egg opened up before it was fully grown.  There is more yolk than turtle.