her 12-year-old son derek. tamara lived just down the street. >> kay was a sweetheart. you never saw her upset, never saw her mad, always smiling, just a joy to be around. >> what kinds of things did she like to do? >> well, mostly anything dealing with her son and her husband. she was very supportive, always being with them. >> reporter: next door to kay lived becky sears. becky had her hands full, too. she and her husband tony had five kids, including two older sons from becky's first marriage. >> she's one of those people who's very outgoing, one of those, "hey, how you doing," type people. >> reporter: tamara got to know both, but says kay and becky really hit it off. >> they were best friends. they were basically inseparable. and they were together 24/7 almost. >> reporter: the two neighbors became peas in a pod. they worked at the same physical therapy center called healing hands. >> they'd go on vacations with each other. >> reporter: jurgen cowling was their boss. >> when you think of them being around your office, what do you see them doing? >> well, we all get along. you knew they were best friends because they were cutting up on each other. and then they would also tell stories about their sons' baseball, especially during the baseball seasons, 'cause they were best friends, the sons. >> reporter: kay and becky even joined weight watchers together. and the two of them were pretty competitive at the weight watcher thing, huh? >> yes, yes. >> reporter: who's up a pound, who's down a pound? >> yes. every day. >> reporter: and one day in march 2009 began like any other. kay, the little league mom, got up to take derek to school, and becky, the mother of five, left