. >> reporter: back in surfside, allyn kilsheimer told us the investigation doesn't need to take two was hired by the city of surfside hours after the collapse to conduct its own investigation. >> we have to get to the trigger. i always say a building talks to you if you know how to listen to it all right. and it finds a way to support itself or it finally says i give up, i can't support it. i'll fall down. >> reporter: kilsheimer a renown engineer was part of the investigation after the oklahoma city bombing and the 9/11 attack on the pentagon. so where are you in the investigation right now? how far along? >> we're about eig months behind where i wanted to be. >> reporter: that's because kilsheimer is still negotiating with federal investigators for permission to do is own tests on the building samples locked up in that warehouse. is this unusual? >> i've never run into it before. >> not with the pentagon, not with the oklahoma city bombing. >> i've never run into it before. it's very unusual. >> reporter: it took until this past august before allyn kilsheimer was allowed to do thi