Tower Block (2012) on Netflix

Plot summary

Tower Block 31 is condemned and nearly empty, its last tenants waiting to be rehoused on the top floor. Three months earlier a fifteen-year-old, Jimmy, was chased into the building and killed while the neighbours stayed behind their doors. Now someone with a rifle is firing through their windows. Becky, an office worker who woke beside a colleague, reaches the hallway with the others: a young couple, a single mother, a former soldier and his wife, two drug dealers, an alcoholic, and Kurtis, who collects protection money from them. Flats are hit, phones and internet fail, and hand-made posters with three emoticons appear on the walls and doors. The fire escape is exposed, so they force open the lift door, only to find the way down blocked.