Various Seattle ladders and people in staging.
You may be wondering why the number plates say "L5006" and "L5004." King County is divided into three zones (1, 3, 5). Whenever rigs respond outside of their zone, they are to use their zone identifier so there isn't duplication of numbers on the fireground. So SFD units turn around their number plates and identify themselves on the radio as "Ladder 5004." If Tukwila Ladder 54 were to respond into Seattle, since they're from Zone 3, they'd identify themselves as "Ladder 3054."
You may be wondering why the number plates say "L5006" and "L5004." King County is divided into three zones (1, 3, 5). Whenever rigs respond outside of their zone, they are to use their zone identifier so there isn't duplication of numbers on the fireground. So SFD units turn around their number plates and identify themselves on the radio as "Ladder 5004." If Tukwila Ladder 54 were to respond into Seattle, since they're from Zone 3, they'd identify themselves as "Ladder 3054."