For TTC riders already irked by an impending fare hike, Wednesday’s subway shutdown felt like chaos.

But transit officials who plan for the unexpected say the system’s response to the six-hour service stop on the Yonge line went pretty much by the book.

Amid the frustrations with crowding and some miscommunication, protocols and procedures clicked into place, insists TTC spokesman Brad Ross. Certainly, for the 300,000 or so patrons who were massively inconvenienced, things could have been worse.

A contractor cut through the road covering the subway and, for a brief period, created “a very, very dangerous” situation, Ross said Thursday. “At any time that slab of concrete could have fallen through to the track.”

TTC emergency procedures kicked in around 2:30 p.m., minimizing the danger.

“In terms of the protocol with getting the subway stopped, putting shuttle buses on, all those things worked as they should, which is with tremendous precision,” said Ross.