Timeline of the Black Mesa incident

This timeline of the Xen Invasion covers the period from 6 December 2000 to the present day (January 18, 2001).

Timeline of the Xen Invasion
Black Mesa Incident      (up to 8 December 2000) North American Xen Invasion      (December 9 – December 14 2000 ) Extended Invasion (South America, Europe, Africa and North Asia)      (December 14 – December 25 2000) Late Stage Xen Invasion      (December 25 – January 14 2000 ) Combine Invasion      (January 15 2000)

Post-Black Mesa incident (Up to December 8)

December 6, 2000

• 8:58 A.M.; The Anti-Mass Spectrometer suffers an accident during a test on Xen crystal GG-3883 that caused hundreds of smaller Xen creatures to flood into the Black Mesa Research Facility that kills 344 scientist and security personnel and is considered the start of the Xen Invasion, and the eventual cause of the collapse of civilization and Seven Hour War.
• 9:13 A.M.; Headcrab spotted in Santa Fe, New Mexico, killing one and was killed by Santa Fe's police department. At the time, no one suspected the Black Mesa Complex as being the main reason.
• 9:27 A.M.; Massive group of Antlions would be spotted outside the Black Mesa Complex as the disaster becomes known to the government including the New Mexico government, but the public was not aware until twenty minutes afterward.
• 9:30 A.M; 146 deaths occur at the Black Mesa Topside facilities.
• 9:35 A.M.; A "visibly green shockwave" mildly impacts Santa Fe and was reported being seen as far as Albuquerque and Colorado Springs at 9:40 A.M. 34 people are injured through heart attacks, mostly elderly. Power is shut off at locations nearest to the epicenter, in settlements like Dixon, New Mexico, and Springer, New Mexico. Outside of a circle of 10 miles, mild technological errors like faulty internet would be reported.
• 9:40 A.M.; The U.S. Government would become formerly aware of the major nuclear accident at the Black Mesa Research Facility, and demanded administrator Wallace Breen's current location and information on the ongoing accident, and at this date, 930 scientists and guards have died inside the Black Mesa Research Facility and assisted Top-side facilities.
• 9:47 A.M.; The Emergency Alert System would alert the citizens of New Mexico of a "disaster of unknown type" that was occurring at the Black Mesa Research Facility, calling for the evacuation of all residents within a 75-mile radius of the facility and accompanying application centers (existing in Albuquerque and Santa Fe). Several aid centers in South Colorado and North New Mexico would be set up to assist in the evacuation of 1,377,939 people that were in the immediate vicinity (75 miles) of the Black Mesa Research Facility.
• 10:00 A.M.; The Black Mesa Incident ceases (not the Resonance Cascade, which lasted for seconds because of the explosion), but the events of the day continue as hundreds attempt to escape the complex. Xenian fauna floods into the Black Mesa Research Facility, causing the deaths of hundreds of others.
• 10:12 A.M.; Santa Fe had massive sections of Xen fauna be transported into city limits through small interdimensional portals with "Green lights."
• 10:30 A.M.; The UN is told about the events at Black Mesa very loosely, and rushes to the scene to gain knowledge alongside news crews and government agents with all of them noting the appearances of 'unknown hostile creatures.' (Xen fauna)
• 10:35 A.M.; Gordon Freeman wakes from being knocked out by the Anti-Mass Spectrometer, killing a headcrab after waking up.
• 10:43 A.M.; The highly trained Hazardous Environment Combat Unit (HECU) would flood into the site, killing many of scientists, security, and Xen creatures. The HECU would also kill any UN and news crew members that would attempt reconnaissance into the site.
• 11:33 A.M.; the U.S. Government would cut all communications inside and outside the site, and the United Nations wouldn't be aware of the war crimes that the HECU were committing alongside the incredibly alarming transportation of hundreds of Xen creatures into Black Mesa.
• 12:15 P.M.; Vortigaunts seen in Santa Fe, apparently communicating with members of the public before attacking, showing remorse.
• 12:29 P.M.; First massive Xen infestations seen in the Top-Side facilities of Black Mesa, spreading to cave systems near the Black Mesa Complex.
• 12:53 P.M.; Barney Calhoun escapes the facility alongside two other scientists through Xen, causing a portal opening up in the former Whitehead Teleportation Center that helped in the Xen Invasion of Black Mesa.
• 1:54 P.M. Sector I is evacuated completely, with the structure completely collapsing after a Xen infestation takes place inside the sector.
• 2:33 P.M.; Facilities as far as the Aperture Labs facility in Wisconsin and the University of Miami begin reporting some "unknown" creatures, allegedly of Xen origin.
• 2:53 P.M.; Dixon, New Mexico, reports the creation of large sand depression-like disturbances around the town, later confirmed to be Sand Barnacles and are of Xen origin.
• 4:40 P.M.; Washington D.C. sees several Xen creatures be transported onto streets through green "particle storms".
• 4:49 P.M.; A State of Emergency is declared by President George W. Bush, finally acknowledging that there's "an unknown hostile force" present in Black Mesa.
• 5:12 P.M.; Mass Evacuations in Arizona, Colorado, California, Kansas, Nevada, Oklahoma, Texas, and Utah take place as Xen fauna begins to effect those states along with New Mexico, with 38% of the population being evacuated successfully.
• 5:38 P.M.; President George W. Bush began to target the facility with airstrikes to suppress the Xen invasion.
• 6:23 P.M.; A massive explosion near the Hydro plant allows personnel to view Xen for a short time, a portal reportedly being formed and closed in just three minutes, allowing dozens of Xen fauna to flood into the facility.
• 6:49 P.M.; First reports of real life zombies would come out of the New Mexico area caused by Headcrab attacks.
• 8:12 P.M.; A Rocket from inside the Black Mesa Research Facility is launched to cease the Xen invasion, successfully taking place and the Xen invasion near the Black Mesa Research Facility would be stopped.
• 8:58 P.M.; Twelve hours have passed since the incident and 2,103 casualties have taken place involving the HECU, news crews, security and scientist personnel, and United Nations personnel.
• 9:12 P.M.; Large areas inside the decommissioned Black Mesa Silo are taken over by Xen Fauna, either being converted into large-scale alien factories that the Nihilanth used to generate more so-called alien grunts and alien controllers.
• 9:38 P.M.; First photos of Xen Fauna are leaked online as all contact in the Black Mesa facility was cut, leading news crews to release them hours after because of their cut communication.
• 10:54 P.M.; Xen Invasion survival guides are formed online through the government and by civilians that live in the surrounding areas of Black Mesa, allowing anyone to evacuate.
• 11:37 P.M.; Thirty-nine scientists are seen evacuating from the Black Mesa Research Center as Xen fauna follows closely, being saved by volunteers of the Santa Fe Police Department's evacuation procedure.
• 11:59 P.M.; The President is told to remain awake for a massive response against the Black Mesa Research Facility, with 39 new squadrons of HECU soldiers would flood into the facility to wipe out Xen fauna.

December 7, 2000

• 1:22 A.M.;
• 7:55 A.M.; Black Mesa is destroyed by a nuclear weapon and was either launched or detonated on ground, with both being debated. Any United Nations personnel, news crews, or government agents located on the site not yet evacuated by the Hazardous Environment Combat Unit were wiped out alongside most of the top-side facility.

December 8, 2000

Areas that issued a state of emergency relating to the Black Mesa Incident, starting from early December 6, 2000 to December 8, 2000.

• 1

Xen Invasion combined with the Seven Hour War (January 15 2000)