The ceiling of the structure was not in good condition. The fiberglass was wearing off. It needed to be fixed immediately to avoid any accidents. It could directly and adversely affect lungs of anyone who enters the tunnel. Fixing it was a must to do job.
Without wasting any time, they immediately removed the fiberglass from the ceiling. The second picture you see above, is the picture of what is looked like after removing fiberglass. Yes the tunnel wasn’t safe. They understood that of they want to explore it safely, they will have to revamp and remodel the whole place.