Funny Games U.S.

The film begins with a loving family - George Farber (Tim Roth), his wife Ann (Naomi Watts), his son Georgie (Devon Gearhart) and their dog, arriving at their lake house. Their next-door neighbor, Fred (Boyd Gaines) is seen with two young men, Peter (Brady Corbet) and Paul (Michael Pitt), who seem to be their friends or relatives. The two young men come over to borrow eggs. Ann is in the kitchen cooking while George and Georgie are outside by the lake, tending to their boat. They seem friendly, and they use Georges golf club. When the men depart with the eggs they soon return with them broken. After asking for more eggs which also end up broken, Ann becomes frustrated, but when George tries to force the men to leave, Peter breaks George's leg with the golf club and they take the family hostage. Ann goes to call for help on the family's cell phone, but finds it unusable, having been earlier dropped in the sink by Peter. Paul then guides Ann on a hunt to find the family's dog, which he had killed with George's golf club. When the family's other neighbors arrive for a visit, Ann passes the two men off as friends until the visitors leave.The family is forced to participate in a number of sadistic games in order to stay alive. Paul asks if the family wants to bet that they will be alive by 9:00 in the morning, though he doubts that they will be. Between playing their games, the two men keep up a constant patter. Paul frequently ridicules Peter's weight and lack of intelligence. He describes a number of contradicting stories of Peter's past, though no definitive explanation is ever presented as to the men's origins or motives. At one point, Georgie tries to escape and runs to the gate. He attempts to climb the locked gate but changes his mind and goes to the neighbors' house passing through the water. Inside the house Georgie attempts to shoot Paul with a shotgun, but the gun fails to go off. Paul returns him to the living room, along with the shotgun. After a few more games, the men play a counting-out game between the family members on the basis that whoever gets counted out will be shot, but Georgie suddenly panics and makes a run for his life, which results in Peter shooting him dead. He and Paul then leave, Paul a little annoyed that Peter didn't follow the rules of their game to the letter.George and Ann weep for their loss, but eventually resolve to survive. Ann flees the house while George, with a broken leg, desperately tries to call for help on the malfunctioning phone. Ann struggles to find help, only to be re-captured by Peter and Paul, who return her to the house. Stabbing George, the men attempt to force Ann to choose for her husband, between a painful, prolonged death with the knife or a quick death with the shotgun. Instead, Ann seizes the shotgun on the table in front of her and kills Peter. Enraged, Paul confiscates the shotgun and starts looking for the television remote. Upon finding it, he literally rewinds all the occurrences back to before Ann grabs the shotgun, thereby breaking the fourth wall. On the 'do over', Paul snatches the shotgun away and admonishes her, saying she isn't allowed to break the rules. They then kill George and take Ann, bound and gagged, out on the family's boat early the next morning. Around eight o'clock, they nonchalantly throw her into the water to drown, thus winning their bet. They dock at the house of the neighbors that had previously visited the family, and request some eggs, thereby restarting their cycle of murder.

Question: Why was the phone unusable when Ann tries to use it?
Answer: Peter drops it in the sink.