What kills the aliens in the movie Independence Day?

Answer 1

Jeff Goldblum and Will Smith's characters fly the crashed UFO into the aliens' mothership, and infect the mothership with a computer virus that causes the force field -- or whatever it is -- that shields the UFOs that are hovering over the city to fail. They also bring along a nuclear missile to destroy the mothership.

Meanwhile, on Earth, jet fighters in the U.S. and around the world are poised to attack when the aliens' shields are down. Jeff Goldblum and Will Smith's characters successfully infect the mothership and cause the shields to fail, and the jet fighters start attacking. But even without the shields, the ships are too big and too strong, and the missiles don't even come close to destroying them.

So, the alcoholic father guy flies his jet up into the center of the ship, where the laser or whatever it is that's supposed to destroy the city is. He dies, but his plane jams up the laser and causes the ship to start blowing up. When the word gets through via Morse Code to all the other cities around the world, they start attacking the centers of the ships, and pretty soon all of the ships that are hovering over the world's major cities are destroyed.

Will Smith and Jeff Goldblum's characters successfully blow up the mothership with the nuclear missile, and escape with their lives.