Sector D

{{Location Infobox
|image=FileSector D composite.jpg|250px
|name=Sector D
|destroyed=200-, during the Black Mesa Incident
|location=Black Mesa Research Facility
|era=Black Mesa Incident
|affiliation=Black Mesa
{{Quote|Hey, what the hell are you doing down here? Get topside! I hear troops are coming in to save us!|Black Mesa Security Force|Black Mesa security guard|Half-Life|FileC1a2 ba bullsquid.ogg}}

'''Sector D'''''Half-Life'' is one of the seven main CategoryBlack Mesa Sectors|SectorsFileTram map 01.png|Black Mesa Transit System map of the Black Mesa Research Facility. It is connected to the Yellow Line of the Black Mesa Transit System.

==Administration Center==
{{Main|Office Complex (chapter)}}

The Administration Center''Half-Life'', sentences.txt is a location featured in ''Half-Life'' in the chapter ''Office Complex''. It is a large underground complex where the bureaucratic aspects of Black Mesa's upkeep take place along with some limited research. The floors are mostly covered with black and white tiles placed in a checkerboard fashion, typical of the area. As suggested by the name of several texture files used in the area, many parts of Sector D, notably the Administration Center, were built in the 1950s, during the WikipediaCold War|Cold War era.''Half-Life Prima Guide''

FileFinal c1a2 01.jpg|The basement.
FileC1a2 basement.jpg|Sparking electrical wires blocking the hall.
FileFinal c1a2 02.jpg|The executive lounge.
FileC1a2 office.jpg|The flooded laboratory.
FileFinal c1a2 04.jpg|Inside the flooded laboratory.
FileOffice Complex Headcrabs.jpg|Crate puzzle.
FileC1a2 storage.jpg|Storage room.
FileC1a2d barney.jpg
FileC1a2a offices.jpg|The administration offices, first floor.
FileFinal c1a2a 01.jpg|Scientists getting pulled by an unseen monster through an air duct.
FileC1a2a hall.jpg
FileC1a2a soda.jpg|The vending machines.
FileC1a2b cafe.jpg|The cafeteria.
FileBM_freezer1.jpg|A large walk-in freezer.
FileBM freezer2.jpg|Ditto.
FileG-Man door.jpg|The G-Man behind a locked door.
FileC1a2b window.jpg|Scientist jumping out of a window.
FileC1a2b shaft.jpg|Dangling scientist in the elevator shaft.

==High Security Materials Storage Area==
{{Main|"We've Got Hostiles"}}

The High Security Materials Storage Area is a location featured in ''Half-Life'' in the chapter ''"We've Got Hostiles"''. It is a large Cold War era storage facility above the Administration Center. As the HECU|military have just invaded the facility, many Sentry Guns and Laser Trip Mine (Half-Life)|Laser Trip Mines have been installed, targeting civilians and alien creatures. Most areas are separated with heavy fire doors that will close when their emergency button is pressed.

FileC1a3 silo.jpg|The door to the Silo D.
FileC1a3 zombie.jpg|The security booth.
FileC1a3 fire01.jpg|Fire door.
FileC1a3 fire02.jpg|Ditto, closed.
FileHL BMRF HighSecurityMaterialsStorage.jpg|Storage area.
FileC1a3 soda.jpg|Beverage machines.
FileC1a3 cafe.jpg|The cafeteria.
FileC1a3 area.jpg|Storage area.
FileC1a3a soldiers.jpg
FileC1a3a storage.jpg
FileHL BMRF StorageArea3.jpg
FileC1a3b surface.jpg|The surface.
FilePlaceholder noimage.svg|The central ventilation shaft.

==Silo D==
{{Main|Blast Pit}}

Silo D is a location featured in ''Half-Life'' in the chapter ''Blast Pit''. It is a large abandoned Cold War era missile silo that houses the Experimental Propulsion Laboratory used for testing rocket engines. It is connected to the High Security Materials Storage Area by an old decommissioned rail system. It houses three silos.

Silo D-01, Engine Testing (green-coded) is located in the middle of the silo. It is the largest and most important of the three. This is where the engines are actually tested. Three huge Tentacle creatures occupy the silo. The other two silos are directly connected to this silo, and can be only accessed through here.

Silo D-02, Power Facility (green-coded) provides energy to Silo D-01 and is accessed through the lowest door of the central chamber. Silo D-03, Wind Tunnel (yellow-coded) contains a huge propeller and is accessed from the upper door inside Silo D-01. The nearby Fuel Room contains the fuel and oxygen reserves provided for the Silo D-01 engines.

FileC1a4 barricade.jpg|Barricade.
FileC1a4 elevator.jpg|Freight elevator.
FileC1a4 tunnel.jpg|Abandoned rail system.
FileC1a4 waste.jpg|Radioactive waste.
FileC1a4k outside.jpg
FileC1a4b squid.jpg
FileC1a4b bridge.jpg
FileSilo tentacle01.jpg|The control room.
FileTentacle pit.jpg|Tentacles.
FileC1a4e fan.jpg|Massive fan.
FileC1a4d fuel.jpg|The fuel room.

FileC1a4f0005.jpg|The power generator.

FileC1a4g0000.jpg|The tunnel beneath the silo.
FileC1a4g0001.jpg|The base of the Tentacles.
FileC1a4g waterfall.jpg|Radioactive river.

==Behind the scenes==
According to the unused textures, the train hub in Sector E was originally part of Sector D.

==List of appearances==
===Main games===
*''Half-Life Blue Shift'' {{C|Black Mesa Transit System map only}}

*''Half-Life Day One'' {{1st}}
*''Half-Life 2 Raising the Bar''


|title=Half-Life Alpha|''Half-Life'' Alpha progression
|before=''The Portal Device''
|after=''The Security Complex''
|title=''Half-Life'' story arc journey
|before=Sector B
|after=Sector E Transport|Sector E Materials Transport
{{Black Mesa}}
CategoryBlack Mesa Sectors