How does the author use foreshadowing in When the Tripods Came?

The narrative, recounted from the first person perspective of mid-teen protagonist Laurie (short for Laurence), begins with Laurie and his friend Andy witnessing the attack of a tall, mechanical, three-legged vehicle (referred to as a Tripod) on a nearby farmhouse. The boys watch as the Tripod destroys the house but is itself destroyed by military forces. This foreshadows Tripod gaining popularity anf having a following.