specificply designed casons were lowered to the floor of the bay. credibling would take place through the holotubes until they reached bedrock of the this was not the most dangerous. once the foundations were laid, then work could begin on the towers. men would now be working hundreds of feet above the water, but they seemed oblivious to the dangerous and, in fact, many seemed to thrive ton. al was known known was the king of the high steel in his bridge- boyding days and now 82, he recalls the only doubt he had work on the bay bridge is that it might fall down. >> i worked on a lot of bridges and a lot of others burb nothing like this. this was new to me. >> reporter: what made it different? >> well, the thrill, and just the guts to go up there and do it and all the thrills and every minute you think the whole thing is gone. i used to look across and all the way to the cable and see 28 and 7/8th diameter and i hope those engineers are right. [ laughter ] >> reporter: the engineers were right. for 50 years the bay bridge has been the workhorse of ba

. >> up next, chef gavin cason. "know the species, know the stain."aster sunday is a popular time to gather families and friends for lunch. >> instead of serving the traditional ham or lambs, gavin casson is here to make a tart. >> we'll change it up and keep it vegetarian. this is going to be a crimini mushroom chart. we start the pan with olive oil and garlic. we'll roast off the mushrooms. you can use any mushrooms you want for this. >> these you prefer? >> i prefer these because i think they are very affordable. i think anybody can get them. that's important. >> is there any nutritional value to mushrooms? >> of course there is. it's all about how much do you eat and how much fat you put with the mushroom. >> but they are not high in calories? >> no. >> little pinch of salt. >> whenever you cook mushrooms, when you add the salt you, have to know it's going to drain the moisture. the water comes out and you have to let the water evaporate. you get this right here. >> what's happening down here? >> we'll sweat some shallots, which we've done and gar