( CNN ) -- For decades , Mike Wallace defined the image of the hard-charging investigative reporter . News of his death at 93 came Sunday and with it a multitude of remembrances and assessments of a complex man . Wallace 's longevity and his medium -- the TV network -- put a face on investigative reporting for the public . His career reflected how investigative journalism evolved from the 1950s into the 21st century -- and showed why we still need it . We watched his work on `` 60 Minutes '' go from undercover tactics and ambush interviews in the 1970s to pieces that relied more on documents and analysis -- and in which targets were not entirely surprised by what was coming . We also watched as Wallace showed how complex and confrontational investigative reporting can be . He spoke openly of subjects dodging interviews and of management and corporate interference in investigative stories . He acknowledged many of his own flaws and revealed his clinical depression resulting from the stresses of the work . We watched too as he underwent two major controversies that would have demolished other careers . One was a $ 120 million libel suit by Gen. William C. Westmoreland over a story that said the military had deceived the American public about the size of opposition forces during the Vietnam War . The suit was eventually withdrawn but not before it had damaged reputations and sent Wallace into depression . The second was over an investigation into the tobacco industry that led to a fierce internal dispute at CBS on airing the story . Eventually , all the information came out and Wallace criticized his own bosses at CBS . But the controversy still resulted in a film highly critical of the network and Wallace 's handling of the story . In addition to those controversies , his methods periodically came under attack from inside journalism , and friendships were lost and colleagues estranged or disillusioned . However , the public stuck with him -- perhaps because he continued to give hope that liars could be exposed , that dangerous practices could be stopped and wrongheaded policies overturned . Backed by a series of talented reporters and producers over the years , he was the front man -- the `` closer '' so to speak -- for teams of investigative journalists and for the public . In the theater of the interview , he conveyed the outrage and skepticism of journalists who spent months digging for the truth . One of his former producers , Charles Lewis , wrote Sunday , `` Mike Wallace will go down in history as the finest investigative interviewer on the most popular and most honored network television news program in U.S . history . '' Lewis , a founder of two nonprofit investigative journalism centers , added , `` At 60 Minutes , he literally set the gold standard for fearless , 'tough but fair , ' go-for-the-jugular questioning and showed the world and the profession how investigative television news could look , should look . '' Wallace also exemplified a very American attitude that no matter how powerful someone is , he or she is expected to answer to the public for actions taken and mistakes made . When he confronted someone , many viewers felt Wallace represented their frustrations and spoke for them . When Wallace said the subject of an interview had to be kidding , he really meant the subject had to be kidding everyone watching . Before the camera , he embodied the democratic attitude that everyone is equal and everyone is accountable . In the end , one might wonder how he could continue to get those interviews after all those years of blistering confrontations , but I got a clue in 2000 . At the time , I was executive director of the professional organization Investigative Reporters and Editors and Wallace had been invited to be on a showcase panel at the annual conference in New York City . He came half an hour early and cheerily talked with the conference staff . But while waiting backstage he suddenly said he needed one of his well-known catnaps . We offered to get a cot , but he said no thanks , folded his suit jacket inside out into a pillow , lay down on the floor and promptly fell asleep . For 10 minutes the staff delicately stepped over and around him . Then he got up , completely alert , thanked everyone for inviting him , and smiling went on stage to chat with a thousand journalists . I suspect it was that kind of regular guy attitude that got so many to talk to him , to believe in him , and even some of his targets to forgive him . The opinions expressed in this commentary are solely those of Brant Houston .
Brant Houston : Mike Wallace , who died Sunday at 93 , defined image of hard-charging reporter . He says Wallace reflected evolution of investigative reporting over decades . Wallace exemplified the attitude that people in power should be held accountable , he says . Houston : Wallace spoke openly of corporate interference in stories , and of his depression .