In Zindel's The Pigman, what is Lorraine's nightmare about? What incident does the dream foreshadow?

Lorraine has a dream that she is in Mr. Pignati's house.  She is forced to walk into his pig collection room.  Once in the room, she sees the pigs on a black coffin.  Lorraine believes that the dream is a bad omen of sorts.  She's not wrong either.  The dream does foreshadow two heartbreaking events.  

The first event is the death of Mr. Pignati's pig collection.  John decides to have a small party at...

Lorraine has a dream that she is in Mr. Pignati's house.  She is forced to walk into his pig collection room.  Once in the room, she sees the pigs on a black coffin.  Lorraine believes that the dream is a bad omen of sorts.  She's not wrong either.  The dream does foreshadow two heartbreaking events.  

The first event is the death of Mr. Pignati's pig collection.  John decides to have a small party at Mr. Pignati's house while Mr. Pignati is still recovering in the hospital.  Things get out of hand when Norton shows up, and Norton destroys the pig collection.  Lorraine's dream shows the pigs on a coffin, so it basically hints that the pigs will die.  

The dream also foreshadows Mr. Pignati's death.  At the end of the novel, Mr. Pignati suffers another heart attack, and this time it kills him.  The coffin in Lorraine's dream is not only meant for the pigs, but also for Mr. Pignati.