Bicycle rides are making me a vigilante

On the way back from Sunflower Cafe while we were on the bike trail, we saw 4 teenage girls scurrying out of the brush next to the river.  They were carrying sparklers.  As we passed, we heard them say something about not being able to put it out.  My dad and I kind of passed the area, then we heard a crackle.  The obvious sound of something on fire.  We had ridden about 50 feet, so we turned around.  As we got back to where the girls were, we see the brush ablaze.  And we see the 4 girls who started it, walking away from the bike trail to the street. 

A guy was already on the horn to 911.  My dad yelled after the girls, but after one look back, they kept walking.  He and another guy started to put out the fire with their water bottles and by throwing dirt/sand on the flame, I hopped on my bike to find out where we were on the bike trail.  I was pretty sure no one knew which mile marker we were at and I needed to find those dumb fucking kids.  I rode after them and as soon as I got to the edge of the street, I yelled to them.  I needed the names of the streets we were at.

"Hey!  What street is this?"

"Umm...I don't know."

"Well fucking LOOK then.  You started a fucking fire.  And now I've got to tell the fire department where we are!"

"Umm...I can't see the sign yet."

"Then fucking run!"

So they hurried to where the sign was, yelled back and I called 911 to let them know where the fire was.  I watched them as they walked away...and hindsight says I should've told them to stay put.  I would've followed them while on the phone, but the last time I did that...things didn't go so well.  After I got off the phone, I rode down to see if I could figure out where they were, but I didn't see them.  I got a good look at two of the little shits, but couldn't remember anything about the others.  I let the police department know the description of the girls and my information and Dad and I started on our way home.

Not only am I angry that those assholes started a fire, didn't even TRY to help put it out, walked away KNOWING a fire was happening without calling 911, but they made me ride an extra mile looking for them.  I was already tired.  The lack of consideration kids have these days.