A single warning is just okay

I was right at my corridor this evening enjoying the cool breeze blowing, gently sipping my soft drinks. Not long after, i saw some couple of kids, climbing an orange tree just to have some oranges. Among this kids is the son of my landlord, with my mind telling me there is danger in what they are doing, i shouted at them and scared them away. I didn't know they were hanging around just for me to lose focus on them. I heard my phone rung and i ran inside to get it, before i got back to the corridor, i already saw this kids back on the tree.
I went to them but this time in a calm and friendly manner, i told them that they might get injured with what they get themselves involved in, they nodded in accordance and agreed to let the tree be.
Exactly forty five minutes later, i heard a loud cry, and alas my landlord kid left hand is broken, i was told he fell from the tree and broke his arm, a scan was run on the hand and its been plastered.
Assuming he had listened to me earlier, this might not have happened, a word is enough for the wise.