Hi Cyn
Sounds like a great topic. Here's a few ideas.
You could introduce community helpers individually. For example talk
about what Firemen do. Read a story about firemen.
You could probably get a poster on fire safety from your local fire
department.
Teach fire safety and have the children act out the part of a fireman
by observing and then reporting on safety starndards in the classroom,
the school and in their own home.
You could bring in community helpers ie. firemen, ambulance drivers etc.
and ask them to talk to the students about what they do, maybe show a
video or a few slides. Hope this helps.
Lin