How to make low destroyed bridge?

[Warmowed]

Hello I'm trying to figure out how to make a low concrete bridge that starts out destroyed. I can make bridges (high & low) that start out built and I can make high bridges that start out destroyed.

In the particular map I'm working on I have confirmed the location of the repair huts are good, but I can't make a destroyed low bridge work. I went looking through all of the official built-in maps for examples and the best I found was mayday's low wood bridges. My suspicion is that they edited manually the overlay (not the overlay data). I tried this out on my map and edited the overlay across the width of the bridge(3 tiles wide for each section) however this didn't work as intended. There is something I must be missing but I'm not sure what. Any advice?

[McPwny]

i dunno, try spawning a navy seal next to the bridge with a script to blow up the bridge and delete itself when the map starts or something

[[YF]_Revive]

I also want to know

[McPwny]

did you think i was just being sarcastic? 

no but really action 63(apply 100 HE damage at waypoint...) works just fine on high bridges...