bobby singh was in the front of the house. i kept trying to holer to him so he would know i was outside. but in the thick gray and black smoke, he couldn't see me. and i just hope he heard me. >> out of earshot from wayne, bobby still has no idea that his friend has escaped. >> when he pulled up, bobby singh had tears in his eyes. he was telling my son that he couldn't get me out of there. he tried. so he brought him over to see me and saw me in the driveway and started to cry. >> the fire department later determines the fire's cause to be improper disposal of smoking materials. >> i will tell you he demonstrated an act of courage and bravery. >> a few weeks later wayne's son paul presents a resolution to the waltham town council honoring bobby singh. >> you have to pause and put yourself in his shoes at that very moment and ask, would you have done what he did? we all say we would, but really would you? his son is with his him here. >> god gave me a chance, gave me strength to save somebody. that's what i did. >> yes, i consi

casey singh from a medical center divided the seniors into two groups. bobby was in the physical activity group. >> the goal was to get folks to walk at least 30 minutes at moderate intensity. we also did some lower extremity strength and some flexibility. exercises. >> reporter: instead of exercise, carol's group attended health education sem mars on different topics of interest to seniors. >> we measured how they were thinking what their memory and complex processing and language function at the start of the study. >> i want you to say the name of each picture. >> acorn. dominos. >> reporter: then researchers measured thinking ability again two years later. the study in jama journal of the american medical association found -- >> both groups preserved their cognitive function over the course of two years. they stayed the same which is really remarkable because we would have expected older adults to have declined at least some over two years. >> reporter: so the conclusion from the study is that both seniors who were physically active or mentally active were