A spontaneous, temporary improvised memorial of flowers, messages, and small objects appeared shortly after news of Collier's death.[2] The MIT community wanted to create a permanent memorial, and assembled a committee of students, faculty, and police officers. A public call for ideas was put out in June 2013.[2] The final design for the memorial was unveiled in April 2014, allowing only a year for fabrication of components and construction.
On April 29, 2015, MIT held special ceremonies dedicating the memorial.[5] MIT President Rafael Reif observed that the memorial represented the community coming together after tragedy: "We are held together by invisible forces too".[2]
Architecture
The memorial consists of 32 massive granite blocks precision-shaped under computer numerical control, and fitted together into a shallow open domed arch with 5 radial support wings splayed out like fingers of an open hand.[1][4][2] This shape is a reference to the MIT mottoMens et Manus (Mind and Hand),[1] and to Collier's spirit of helpfulness.[2] The granite material honors Collier's love of hiking through the nearby White Mountains (New Hampshire) with the MIT Outing Club (MITOC).[6]
The architect, J. Meejin Yoon, has written that the heavy stone blocks mutually support each other, expressing strength through unity. They shelter a large ovoid cavity that represents "a passage, a marker, and an aperture that reframes the site".[3][1] The void represents the absence of the slain officer,[2] and is shaped like an oblong stone from a memorial cairn which had been constructed at trailside by Collier's friends from MITOC.[6]
The design was evaluated by Ochsendorf and his students using computer simulations to study its resistance to a major earthquake. Compressive forces on each block were calculated to be in the range of 20,000 to 50,000 pounds (9,100 to 22,700 kg).[4][2] Each joint between the stone blocks was shaped to be perpendicular to the forces transmitted through the joint, visually expressing the invisible forces that hold the structure up.[4][2] The underground foundation, an essential part of the structure, is made of reinforced concrete to resist the spreading forces produced by the shallow arch it supports. The 190-short-ton (170,000 kg) weight of the structure is supported by mini-piles driven to a depth of 30–40 feet (9.1–12.2 m).[2]
The polished, tapered stone blocks were carved to a precision of 0.5 millimetres (0.020 in) using robotic saws and milling machines, and then surfaced with final finishing by hand.[3] The blocks were installed by a specialized team of riggers operating a crane and machinery, under the guidance of Ochsendorf, his team of students, and a construction manager. The temporary support scaffolding was slowly lowered over the span of 8 hours, while the descent of the central 12,000-pound (5,400 kg) keystone was carefully monitored. Predicted to settle 5 to 15 millimetres (0.20 to 0.59 in), the stone was actually measured as descending 6 millimetres (0.24 in).[2]
The memorial is physically sited immediately next to the location where Collier was murdered. An opening in the structure frames a view of the spot where he was sitting in his MIT Police car responding to a call for help, when he was ambushed and shot.[3][7][6][2] Raised stainless steel buttons, encoding Collier's police badge number "179" in Braille, are installed into the pavement beneath the memorial arches, to discourage its use by skateboarders.[2] Smaller granite blocks are placed around the periphery of the memorial, to provide seating for visitors.[2]Honey locust trees provide a living canopy that marks the passage of time.[3]
Humphries, Courtney (May 22, 2015). "The Making of MIT's Collier Memorial". Architect: the journal of the American Institute of Architects. Hanley Wood Media. Retrieved 2015-07-08. Detailed article includes several architectural drawings showing siting, structural components, and foundations of the memorial.