Like many in Orange County, Larry Armstrong a few years ago began noticing the hundreds of tents, makeshift shelters and piles of trash rising on the outskirts of Angel Stadium and along the Santa Ana River near the Honda Center.

As it became clear several hundred people were living there, the chief executive of Ware Malcomb, Orange County’s third-largest architectural firm, decided to do something.

He met with executives at Orange County United Way, the start of a partnership that led to the unveiling of the United to End Homelessness initiative with Armstrong as chairman.