Summary:

The teens of West Ham high are taken on school buses for a camping trip. They return to find their town completely empty, all the exits blocked and no communication with the outside world. They must learn to fend for themselves and how to survive on their own.
Together they must solve a murder, figure out a system for living and what happened to everyone else. The characters boundaries, alliances and decision making skills are tested while they try to do their best to live without any family or adults to help them.

Personal Opinion:

I thought this show was very realistic and interesting. There are plenty of twists and turns as well as some very lovable and not so lovable characters.
Like most teenagers, they start off partying and taking advantage of having no adults around. Their attitudes begin to shift when they realize they may be stuck there alone for a while and decide to ration food and set up a society together. Guards are assigned for safety, a leader is chosen and they even organize a getting home committee. Things escalate to not so ideal circumstances though as their society begins to crack and fall apart. The teens begin to fight for power and start taking matters into their own hands when things don't work out the way they want. One of the teens even ends up pregnant and fearful with no doctors around.
The actors did a great job bringing the characters to life and making them believable.
The side stories of certain characters keep things interesting and make it hard not to binge watch.

I wanna say it's a shame that it got cancelled, but to be honest I didn't really cared much for the show.
It was a bit too dark for me.