That nice, polite kid who visits your house may not always be what she appears. Give your child and the school your cell phone number. If you can't be reached easily at work, invest in a pager. Tape a quarter somewhere it will stay for emergencies only. Create a connection to another adult and make sure it works.
Nobody is always available.
Your kid, the school and the alternate adult need to know what to do when you can't be found. Stay in touch. The more you know about your child's environment, the safer they are. They may 'just die' if you go to school. Go to parent nights.