CLAIM: Jesus’ main emphasis in these four parallel chapters is to describe the Great Tribulation just before His Second Coming. He predicted the siege of Jerusalem and the destruction of its temple (Mt. 24:2) by the Roman armies in 70 AD. This tragedy foreshadows the siege of Jerusalem at the end of the age (Joel 3:2, 12; Zeph. 3:8; Zech. 12:2-3; 14:2; Rev. 16:14). Many details in these four chapters make it clear, that Jesus’ words go far beyond the events of 70 AD to describe the events at the end of the age. For example, Jesus describes the time of the Great tribulation as the worst time in history (Mt. 24:21). God shortens this time frame to three and a half years in order to keep the entire human race from being physically killed (Mt. 24:22). Jesus said this hour would come as a snare upon the entire earth, not only Israel (Lk. 21:35). The Great Tribulation will surpass all other crises in history, including the one million people who died in 70 AD and the fifty million who died in World War II. Neither 70 AD nor World War II threatened the existence of the human race. Jesus said this time of tribulation would not happen until after we see the abomination of desolation (Mt. 24:15), which includes a worldwide Antichrist worship system centered upon the image of the Antichrist, and the mark of the beast (Rev. 13:13-18). None of these details were fulfilled in the Jewish revolt against Rome (66-70 AD).
Matthew 24; Luke 21; Mark 13
Both future and past fulfillment items are included in this passage.
Luke 17
True. This correlates to the second half of the Matthew 24 dialogue relating the Second Coming, and is unfulfilled.
Matthew 24 and the related chapters are discussed in further length in other places (see here, here, or here). In short, the events seeming to comprise the 70AD destruction of Jerusalem were and must be interpreted as such, since they are all referring to what was then visible, the existing temple. As the article on Eutheos describes (see the first reference above), there is no need to roll the Great Tribulation events, which are past, in with the second coming events. As such, while the Great Tribulation is fulfilled in the past, the Second Coming portions are yet to be fulfilled, and we are to expectantly watch and wait. Additionally, the claim that the WWII events could not fulfill these events is described in more detail here.
The Luke 17 portion, however, does focus on the End Times events, as is seen in the parallel language of lightning in the east being seen in the west.