(I am extremely sorry for the late update...)

1) A father ,mother and their little son were about to cross a road. They watched out for any vehicles... and when they found the road clear,they started crossing. But when they were in the middle of the road, they saw a truck speeding up.
They ran together to the other end and saved themselves at the last moment.
Their son sighed and exclaimed " if we were hit by that truck ,then we four would have died!!"

Q) who's the fourth person the kid is talking about???

I'll put up the answer after I get a few answers in the comments
^-^

Bye bye
Wolfram...