Probably not the one you're talking about, but the construction site and falling senario brings Punch Up to mind
http://www.mangago.me/read-manga/punch_up/me/En/Punch+Up/9/67/
Maybe escape journey http://www.mangago.me/read-manga/escape_journey/nbt/2afc3f0c96c27fb61/Vol2_Ch13/14/
it's the second one it's about a guy to Dad died in the car accident but he confessed to his best friend and that he left Dennis best friend found him in a college and then they started dating and one day there standing up for the School Festival and he almost fell off and when he saw this it reminded it of his dad
I can't remember much from this BL manga except for one scene where the Uke or seme is standing on this high platform for construction and it starts to fall and their partner is on the ground and sees what's happening and I think the two make up from a fight??? I can't remember much or even if that's right but if anyone has a name for the manga it would be much appreciated ╰(*´︶`*)╯♡