The story
The firm was founded in 1970 in Kansas City, MO as Patty Berkebile Nelson Love Architects (PBNL) by R. Bruce Patty, Robert J. Berkebile, Thompson C. Nelson and William Love. Dating to its early history, the firm is dedicated to strengthening the urban core with projects and the civic involvement of firm members.
Two of the principals (Bob Berkebile and Tom Nelson) were members of a joint venture, PBNDML, that designed the Hyatt Regency Crown Center that was site of the 1981 Hyatt Regency walkway collapse.
Architect Edward Larrabee Barnes was the formal master of the hotel. However, two local Kansas City firms merged to formally design the hotel-including a consortium of R. Bruce Patty, Bob Berkebile and Tom Nelson (PBN), and Duncan Monroe Lefevre (DML).
Investigation of the accident determined the failure to be the fault of the structural engineer.
In 1987, Patty, Berkebile and Nelson formed a new firm with David Immenschuh, known as PBNI Architects. They were to design One Kansas City Place which is the tallest building in Missouri.
In 1991, Berkebile, Nelson and Immenschuh were joined by Steve McDowell and became Berkebile Nelson Immenschuh McDowell (BNIM).
From Wikipedia’s article on BNIM, shared under CC BY-SA 4.0.4