Hazardous Environment Combat Unit

The Hazardous Environment Combat Unit or HECU is a special operations branch of the U.S. military that specializes in surviving in harsh environments unsustainable to regular soldiers. They are introduced as one of the antagonist factions in the FPS thriller Half-Life, where their job is to combat the oncoming alien invasion at the Black Mesa Research Facility, and silence the facilities science team in a cover-up operation. They are main antagonists to Goron Freeman, and Barney Calhoun.

Description
The HECU is a special operations division of the United States Marines, consisting of specialy picked soldiers who are trained and readied to operate in harsh environments that include things such as: Thereby making them better qualified than regular soldiers for hazardous situations, however this usually only amounts to a couple baby-sitting jobs. HECU personel consists of squad leaders, grunts, medics, engineers, and snipers, dressed in black and white camoflauge fatigues, and a Powered Combat Vest, with several miscellaneous items such as ammo pouch belts, gas masks, balaclavas, and night vision goggles.
 * Extreme Heat
 * Radio-acitve Materials
 * Dangerous Machinery
 * Explosives
 * Structural Collapse
 * and Treacherously Manuevered Terrain

Black Mesa
The HECUs biggest(and last) mission was to take care of the Black Mesa incident, a large interdimensional rift leaking hostile aliens from another dimension known as Xen. However the HECU were not told where they were going or what their mission was, it was believed to be nothing more than another baby-sitting job by soldiers, but as the soldiers entered the chaos that was the Black Mesa incident they knew it was anything but. It was there that the soldiers received their orders, kill the aliens, the scientists, and especially, Gordon Freeman.

Notable Quotes
"This place makes boot camp seem like Disney Land."

"This mission is way beyond fubar."

"Hey man, you smell that? Smells like..like another baby-sitting job to me, man."

"You've gotta get outta here..listen to me Shephard..those things..they'll kill all of us."

"Don't..go in there corporal..that moster..whiped out my..squad. Aaaarghh."