At 11 & 12 yo - the parents should also be made responsible !
When we were all 11 & 12 we had a fascination with fire as well, but didnt do that cause our parents brought us up to respect peoples property. Now in a busier world, parents arent teaching their kids morals / values anymore. Give them some trees / plants and make them replant each tree, and water them every day... !
At 11 our parents knew where we were every second, down the milko or cornershop playing video games or pinnies. Street lights came on - we were home ! Gotta love that daylight saving thing as a kid