IT STARTED WITH TWO RADIO DJs And a lighthearted prank call to the london hospital where the pregnant duchess kate was recovering from acute sickness. But today, that joke took an unexpected turn,... See More
IT STARTED WITH TWO RADIO DJs And a lighthearted prank call to the london hospital where the pregnant duchess kate was recovering from acute sickness. But today, that joke took an unexpected turn, when the nurse who picked up the call was found dead. Abc's david wright brings us this look at the dark side of practical jokes. Hello, good morning. Oh, hello there. Could I please speak to kate, please, my grter. Oh, yes, just hold on. Reporter: As this prank phone CALL BY TWO AUSTRALIAN DJs WENT Viral around the world. If this has worked, it's the easiest prank call we've ever made. Reporter: One can only imagine that the nurse that put the call through must have been mortified. It is with deep sadness that I can confirm the tragic death of a member of our nursing staff, jacintha saldanha. Everyone is shocked by the loss of a much-loved and valued colleague. Reporter: Today, the duke and duchess of cambridge echoed that sentiment. Their royal highnesses were lo looked after so wonderfully well at all times. Their thoughts and prayers are with jacintha saldanha's family, friends and colleagues at this very sad time. Hello, I'm just after my granddaughter kate. Reporter: Suddenly, that joke at the expense of kate's care givers. When is a good time to come and visit her, because I'm the queen, I need a lift down there Reporter: Doesn't seem all that funny anymore. CLEARLY, THE DJs INVOLVED IN It never could have anticipated this would happen. I don't think they even thought they would besuccessful. Reporter: Today, for the australian djed who made the call, major backlash. Their station apologized wednesday, but today, the station's facebook page got bombarded with outraged messages. Some saying they have blood on their hands. Twitter and youtube have helped make this a golden age for practical jokes. Amplifying humor to a world wide audience. One example, currently making the unds is this brazilian tv footage. Showing people trapped all alone in a broken elevator, only to find they've been joined by a spooky companion. Part of what it makes it so funny is it plays on human fear. What producers try to do is, they add a laugh track. So, the laugh track, the people laughing in the background sort of signal that this potentially bad situation, potentially mean thing, is actually okay and, hence, funny. That laugh track, it is hard to delight in the misery of others. Reporter: Less funny are jokes that target one individual in what could be construed as a mean spirits today, such wayne, an american magician appearing on tv in the dominican republican. The host unexpectedly set his hair on fire. His face is burnt. Reporter: The magician suffered serious burns. A practical joke is be a way to tease someone or bully them. Reporter: Sometimes a friendly joke can go too far. In 2004, many fans thought it was funny when chris klein found his house under siege. A fake hollywood s.W team in this case, under the direction of punked host ashton kutcher. I knew it! Reporter: But earlier this year, someone pun,ed kutcher by sending a real s.W.A.T. Team to his house. The prankster told police there was a home invasion in progress. Some of kutcher's household staff were detained at gun point by real cops with real bullets. Authorities call it s.W.A.T.Ing, it's being something of a mini-fad. Among the other high profile victims this year, miley sicyrus and simon cowell. Clearly, the australians never expected their prank to have deadly consequences. This nurse got caught in the crossfire. Very clearly, it's the case that the royals were the target. Reporter: Mel got the radio show earlier this year, after gaining prominence as a fun-loving contestant on "the amazing race." It still smells. Reporter: Now, she'll have to deal with the fallout from this. If you think about it, there's another obvious person bound to be hurt by this particular practical joke. The anxious royal father to be. His mother will never know his children because she was hounded by the press. Now, more frivolous attention. I am the queen, bow for me. Bow for me. Reporter: And tragically, another life lost. I'm david wright for "nightline" in los angeles.
This transcript has been automatically generated and may not be 100% accurate.