The Battle of Hasbro Mining Pit was a Sentinel SAR (Search and Recovery) mission as well as a rescue mission that took place at Hasbro Mining Pit, a Chimeran prison camp as well as a Conversion Center complex, in Madison, Wisconsin.
On December 20th, 1951. Harley Burl along with 22 other prisoners escaped the Hasbro Mining Pit. Burl stayed hidden near the pit before making his escape during a snowstorm, and following a road where he founded and a hotwiring a car. He was then discovered by a passing VTOL while speeding down the road. Having known that ex-Secretary of War Henry Walker was in the pit, Burl told his information to Chief of Staff William Dentweiler and SRPA Director of Advanced Tatical Ops Major Richard Blake, who were both on a manhunt for Walker for allegations of treason under the order of President Noah Grace.
Blake dispatch an operation with Sentinel Strike Force Zebra under the command of 2nd Lieutenant Nathan Hale, and accompanied by Burl and Dentweiler - who the latter had joined in confirming Walker's capture/arrest - to Madison.
A few hours after Hale was put in charge; six VTOLs, four LU-P Lynx APVs, two M-12 Sabertooths and 72 Sentinels and SRPA Air Force men flew to the Hasbro Mining Pit. Hale led the VTOLs in 1st Lieutenant Harley Purvis' VTOL Party Girl. Upon landing in the outskirts of the pit, M-12 Sabertooths were unharnessed as the rest of the first VTOL squadrons took out Hybrids who were controlling a Chimeran mortar that was raining mortar rounds down into the pit. After capturing the mortar, a team of three took control of it and turned it against the Chimera.
After all troops had landed, a number of brisk firefights had begun as various squads started to tackle their objectives and effectively securing much of the pit. Two Lynxes were provided for Hale, Dentweiler and Burl to be driven, killing remaining Howlers, Hybrids and Drones on the way down. Once reaching the pit, Burl placated the anxious surviving prisoners. Dentweiler demanded the prisoners in identifying Henry Walker, but gaining garbled responses. Burl, however, had bumped into a fellow prisoner who informed him that Walker had been taken to the Conversion Center yesterday along with 23 others. Burl told Hale about Walker's death and reveal everything why the government were after the ex-Secretary of War, as Walker had recorded tapes of Project Omega - an secret government negotiation in which President Grace intended to struck a exclusive truce between the United States and the Chimera. Hale then decided to retrieve the tapes but before learning from Capt. Marvin Kawecki, an acting platoon sergeant, that an advancing Chimeran forces consisting two Stalkers, a Goliath and about 200 Hybrids were approaching the pit from the east. Hale ordered Kawecki to establish an observation post out west, putting their troops in front of some buildings near the pit and to use the captured mortars on the Chimera. Dentweiler was then placed under arrest by Hale at gunpoint, and Burl in organizing the freed 282 prisoners up into alphabetical order and then split them into 30 person groups for them then to be extracted by the VTOLs.
The first VTOL was in the air and in the process of lowering itself into the pit as the two Lynxes appeared and stopped in front of Hale who then ordered them to tackle the Stalkers whilsts the tanks took care of the Goliath, just before the Lynxes left, Hale told Dentweiler that if he wanted to live, he had to keep his mouth shut and stay with him which Dentweiler did. The battle began as the Chimera sent salvo after salvo of high explosives arcing down on the cluster of buildings - the humans forces answered with cannon fire from the M-12's and hit-and-run attacks from Lynx APVs. The defense had managed to fend off the Chimeran forces, apart from the Goliath, with the cost of losing one Lynx. Hale then ordered his forces in flanking the Goliath and having all LAARK-armed Sentinels aimed towards the machine and retreating to a new location, causing to slow down the Goliath and allowing the tanks to get in a new position. The Goliath effortlessly entered the vicinity of the pit, in which Hale, armed from a salvaged Pulse Cannon , had the opportunity in destroying some its exposed reactors and disabling one of its legs, causing it to topple backward from the pit's rim. However, the Goliath was still operational before being finally destroyed by Hale.
Following the skirmish, Hale had anticipated for another Chimeran attack and ordering Sentinel forces to be ready before their extraction. During the entire battle, Dentweiler escaped from Hale's custody and fled inside the pit's conversion center, where it also held Henry Walker. Hale and a Sentinel squad were sent into the center into finding Dentweiler and Walker's corpse. They found Dentweiler already cocooned and infected by Spinners, and was promptly euthanize, and finding Walker among the cocoons along with his tapes. The squad recovered the tapes and destroyed the center with Air Fuel Grenades. Strike Force Zebra was then evacuated before a massive Chimeran force arrive on the scene. Hale would later listen to Walker's tapes and learning the full disclosure Project Omega, and proceeded to carry on Walker's mission three days later in foiling the negotiations in being personally accounted for President Grace's death.