Emergency services in the north-east of England receive a harrowing call from a young woman who has found her flatmate dead at their home in Gateshead. A tiger on the loose in U.S. residential street causes panic.

The horrific story of how Travis the chimpanzee made a brutal attack that would change lives forever. Plus a chilling call from an online predator, and a shift at work that became a life-or-death situation.

In Ohio, a 911 call reveals the aftermath of an attack on a baby. Fog hits the Sheppey Crossing in Kent causing one of the biggest road accidents in UK history. A man makes a 911 call in South Carolina as he attacks his ex-girlfriend.

Dramatic 911 calls and interviews with emergency services and witnesses tell the traumatic story of the Boston Marathon bombing. Plus, in Bristol a neighbour finds a man covered in acid.

A helicopter crash takes place as a wealthy entrepreneur and his friends fly to his ranch in New Mexico. In north London, a van is deliberately driven into a crowd of worshippers outside a mosque.

A 911 call reveals one woman's desperate bid to escape her abductor while he lays asleep next to her. A little boy falls into the gorilla enclosure at Cincinnati Zoo. A bride is shot dead by her new husband.