railing using what's called a load cell. >> the load cell is more or less a scale. it's a series of springs and sensors, and it measures compression and tension. >> florence weighed 110 pounds. to simulate her sitting on the railing, analysts attached a bicycle seat to one end of the load cell. to the other end, they attached a t-bar, to which they applied 200 pounds of pressure. the railing didn't buckle or break. >> somebody from the lab made the comment, "wow, 200 pounds." so, we knew right then and there that any plan to paint the rail as rotting and dilapidated weren't going to work. >> it was beginning to look like the scene had been staged to look like an accident. it was a charge florence's husband, mark, adamantly denied.