Grid Kilo 23 was a sector of the United Nations Space Command city Old Mombasa on the planet Earth.
It consisted of a broad highway, and during the Battle of New Mombasa, a Covenant Scarab was defending this grid sector, along with great numbers of other Covenant forces. A UNSC strike force of three Warthogs and three Pelican Dropships were dispatched over Grid Kilo 23 to attack the Covenant ship that was commanding the Covenant forces in the First Battle of Earth (where the Battle of New Mombasa had originated from).
Marine reconnaisance observing the grid sector noted the high Covenant troop concentrations, but failed to see the Scarab battle walker. As the three Pelicans neared the Scarab, unaware of its presence, the Scarab shot two of them down with its plasma weapons. There were several survivors at each crash site, thought in both cases the pilots perished in the crash. One of them consist of SPARTAN-117, Sergeant Avery J. Johnson, and three anonymous Marines - two with Battle Rifles and one with an SMG. The 2nd is carrying a squadron of ODST and crashed landed in a beach behind hotel zanzibar. The last one was vaporised by the scarab