Need HELP by only discription of BOOK COVER

So all I can describe is 3 kids on the cover 2 boys and 1 girl (I think)
And they are at a plane/train/bus station locker. Its open and a briefcase full of money is falling out and all kids have a surprised look on their faces.

It came out around early 90s.

PLEASE SOMEONE HELP

THANKS

Need HELP by only discription of BOOK COVER