1800s, local flower growers pould pedal their goods at lotta's fountain where market, geary, and kearny streets converge in downtown san francisco. today local growers continue to supply the mart with bushels of bouquets, providing the first crucial step in a day in the life of how flowers get to you. >> people that i know, most of them don't even know that the flower market exists. and if they do, they have no idea that it goes on in the middle of the night. >> and i think that anybody that comes here and sees what goes on in the early mornings, they can see the spirit and how everybody really enjoys it. just look at all these beautiful flowers. this is the larst flower market in the world. it's got every variety possible. and if you can't find it here, it's not available or it's not in season. you're helping your dad today, huh? >> a little bit. >> yeah, that's good. don't forget to go and have a piece of cake over there. >> what's the celebration? >> anniversary, 48 yearsyeah. >> congratulations! >> i started out going to the flower market at 12 years old. i'm giving my age away, but

one more level down and then exit out around the perimeter on exit stairs, over on the corner of kearny and pine you'll see the exit stairs. so the exiting of the design of this building was well thought out. >> and an exit is something that takes you to the street. it just doesn't take you to the lobby. an exit has to get you to the public right-of-way. right sergeant? do we have any questions about building structure of a steel-framed blt? so the question is shouldn't all the fire protection ratings be uniform? >> the general concept is, you want to protect at a higher level, critical elements. the critical element is the column. >> holding the building up? >> holding the building up. that's why it has four hours of protection. i'm hoping that the fire department can get here faster than four hours. >> and the people leave. >> around the people leave, yeah, one of the biggest contents is not protecting the building and contents, but providing the people a sufficient amount of time for evacuation. in san francisco, on rincon hill and south market, under construction right now, we have