I can't believe I haven't posted this before. It's something that's been floating around the Internet for years now. Someone in management at Jack in the Box, a fast food chain with locations mainly west of the Mississippi, was driving into Dallas and leaving a voice mail message for a colleague when he witnessed a traffic accident. His description of the ensuing events was so hilarious that the message was forwarded all over the company's voice mail system, by some accounts causing it to crash.
Predictably, quite a few people contend that the call is fake, but the laughter sounds pretty genuine to me. Snopes cautiously labels its status as "Undetermined," but quotes a statement from Jack in the Box corporate offices as follows:
Thank you for your inquiry. The message that has been in circulation is an actual voice mail message. The incident occurred 5-6 years ago in Texas. I'm not sure how the recording got outside the company or if the employee still works for Jack in the Box, but the recording periodically re-surfaces on the radio and the internet.
Snopes also notes that a man named Michael Childs has stated in interviews that he was the person who left the message and that it was on the level, a live description of an accident he witnessed in Athens, Texas, about 70 miles southeast of Dallas when he was working as a construction manager for Jack in the Box. I'm inclined to think it's real, and in any case it's certainly funny.