The skywalk was under construction during the events of the film. It was used by Colonel Stuart's mercenaries, O'Reilly, Sheldon, Shockley and Mulkey to make sure no one got near the antenna array. Then Dulles chief engineer Leslie Barnes and five of Captain Carmine Lorenzo's SWAT officers arrived. As they were walking on the skywalk, O'Reilly turned off the skywalk to their surprise. As the commander berated him for his behavior, O'Reilly revealed his pistol and killed the SWAT commander, springing the bottleneck ambush. As the rest of the mercenaries fired at the SWAT team, Leslie Barnes went down and the glass near him cut his arm. All of the SWAT officers, as well Shockley, were killed during the shootout.
As Barnes hid, O'Reilly crept quietly and pointed his pistol at Barnes, ready to kill him. Then, John McClane arrived unexpectedly and kicked the vent grate, which fell on O'Reilly's face. Then McClane killed O'Reilly with his Beretta 92. Sheldon and Mulkey fired back at him, but had eluded their firepower. As he went under the working rig where Sheldon was at, McClane fired at him, But Sheldon fired back at him. Then McClane pushed the scaffolding rig down and Sheldon fell from the top of it. The rig then fell on Sheldon, crushing him to death. But another scaffolding above McClane fell on him pinning him down near the skywalk. When Mulkey ran out of ammo of his last magazine, he was coming closer to McClane. But McClane used a pipe to activate the skywalk to grab his pistol. Mulkey saw this and rushed to try to get it. But McClane grabbed it in time and had killed Mulkey with it.After the shootout was finally over, Barnes turned off the skywalk and lifted the scaffolding off of McClane. As Barnes was about to get to the antenna array, it blew up. McClane and Barnes saw the situation had turned against them, so that there was no way to bring their communications back online, and that Lorenzo lost his SWAT team for nothing.
As the skywalk was closed down due to the shootout, Barnes, whose left arm was being patched by McClane, told Trudeau on the satellite phone that Lorenzo's SWAT team were killed and the antenna array had been destroyed. Then McClane heard the sound of static signal and he found a radio near Shockley's body and took it. Barnes told McClane the scrambler must have been activated by the code panel on it and they couldn't listen in without the right code. Barnes said that the radio is a 10-digit penal and it would take forever to break it.
After a moment, McClane listened as Stuart posed as Dulles Tower to talk to the flight Windsor 114 that he would land at runway 29. He realized in horror that Stuart was going crash the plane. McClane gathered some rags, a can of paint thinners and two pipes around the skywalk as he was going to try the save the plane. Barnes handed McClane his coat and helped him down the balcony to the outside of the new terminal. Barnes watched from the annex skywalk as McClane tried and failed to save the passengers on Windsor 114.