A bomb exploded in the kitchen of the Theodorakis' coffee shop. 

It was so sudden:  the earsplitting bangs, the screams, the confusion.  Theo and Doug ran into the kitchen; Mrs. Thodorakis ran out.  Her hair, her face, her apron were splattered with dark dripping red. 
       "Blood," Sydelle Pulaski cried, clutching her heart.
       "Don't just sit there," Catherine Thodorakis shouted, "somebody call the fire department."
        Angela hurried to the pay phone on the wall and stood there trembling, not knowing whether to call or not.  They were snowbound, the fire engines could not reach Sunset Towers.
        Theo leaned through the kitchen doorway.  "Everything's oaky.  There's no fire."
        "Chris, honey, it's all right,"  Mrs. Thodorakis said, kneeling before the wheelchair.  "It's all right, Chris, look!  It's just tomato sauce."  (68-9)

The bomber upset the meeting, at which the heirs gathered to decide what to do with their clues.  Also, the group learned that the shorthand copy that Sydelle Pulaski had made of the Westing will had been found sitting on a table in Hoo's restaurant.  Sydelle acuses various people of taking the shorthand document.  Mr. Hoo mentions that his partner, Grace Wexler, knows shorthand, and that she couldn't understand a word of what Sydelle had written in her notebook.  Sydelle replies that this was because she had written the shorthand notes in Polish.  Nothing was really decided at the meeting, except that the group agreed that, if the game was solved, a slightly bigger share would be awarded to Sydelle because she had the foresight to take notes.  After the explosion of the bomb, the meeting ended.

Source: Raskin, Ellen.  The Westing Game.  New York: Avon Books, 1978.