The primary events of Matthew 24 have not happened yet. The first part of the passage describe general events - of which there certainly have been applications during the church age (plagues, earthquakes, wars, etc.) - though I believe the context is events within that seven year period. If you compare Matthew 24 with Luke 21, you will see that Luke actually describes what would happen during the destruction of Jerusalem, with the prophecy that the nation of Israel would be scattered throughout the world; however, Matthew 24 and Mark 13 are different in what they cover (what happened in 70 AD is similar in some ways to what will happen during the Tribulation, but those chapters describe what will happen during the reign and destruction under the Antichrist).

For example:

70 AD - Luke 21:5-7 And as some spake of the temple, how it was adorned with goodly stones and gifts, he said, As for these things which ye behold, the days will come, in the which there shall not be left one stone upon another, that shall not be thrown down. And they asked him, saying, Master, but when shall these things be? and what sign will there be when these things shall come to pass?

Luke 21:12 But before all these (describing the other events at the end of the church age), they shall lay their hands on you, and persecute you, delivering you up to the synagogues, and into prisons, being brought before kings and rulers for my name's sake.

Luke 21:20-24 And when ye shall see Jerusalem compassed with armies, then know that the desolation thereof is nigh. Then let them which are in Judaea flee to the mountains; and let them which are in the midst of it depart out; and let not them that are in the countries enter thereinto. For these be the days of vengeance, that all things which are written may be fulfilled. But woe unto them that are with child, and to them that give suck, in those days! for there shall be great distress in the land, and wrath upon this people. And they shall fall by the edge of the sword, and shall be led away captive into all nations: and Jerusalem shall be trodden down of the Gentiles, until the times of the Gentiles be fulfilled.

The Tribulation - Matthew 24:3 And as he sat upon the mount of Olives, the disciples came unto him privately, saying, Tell us, when shall these things be? and what shall be the sign of thy coming, and of the end of the world?

From the contexts of these chapters, it is obvious Luke 21 deals with the first question which was fulfilled in AD 70, and Mark 13 and Matthew 24 deal with the other two.

Matthew 24:15-22 When ye therefore shall see the abomination of desolation, spoken of by Daniel the prophet, stand in the holy place, (whoso readeth, let him understand Then let them which be in Judaea flee into the mountains: Let him which is on the housetop not come down to take any thing out of his house: Neither let him which is in the field return back to take his clothes. And woe unto them that are with child, and to them that give suck in those days! But pray ye that your flight be not in the winter, neither on the sabbath day: For then shall be great tribulation, such as was not since the beginning of the world to this time, no, nor ever shall be. And except those days should be shortened, there should no flesh be saved: but for the elect's sake those days shall be shortened.

This is describing events that will only ever happen ONCE to the world - the great tribulation, and this passage indicates it will be Christ's return that will end this time of persecution and destruction. THAT hasn't happened yet - though Luke 21 has (ie. the dispersal of the Jews throughout the world and the time of the Gentiles, which we are still in).