A dad has been arrested for shooting his entire family, killing four of them, including a six-year-old boy, while neighbours initially believed the gunshots were festive fireworks.

Another little tot, barely one year old, is now critically injured in hospital following the devastating attack that claimed four lives on Kitty Hawk Road, Alameda, San Francisco. Neighbours expressed their shock over the deadly shooting that took place on Wednesday night, with many mistaking the harrowing sound for celebratory fireworks.

A resident of the area, named only as Diane, recalled the horror to CBS News: “They were a family of two kids. Two boys just like us. Last night when this was all going down, we came out and somebody said get inside there’s an active shooter – I said ‘Oh my God it’s William’s house! What did you mean there’s an active shooter?’ I went inside and grabbed my baby. It was terrifying.”

Neighbours confessed to being in “complete shock” upon realising that the man in handcuffs was the young victim’s father, Shane Killian, instead of an unknown assailant. While authorities haven’t disclosed the motive behind the gruesome killings, they are diligently questioning the suspect to uncover the events leading to this appalling incident.

In a sombre reflection of the tragedy, Chief Nishant Joshi of the Alameda Police Department gave his perspective on the cruel crime. Speaking to CBS, he declared: “This is a sad and tragic incident,” and solemnly noted: “And I’ll say this, these are the actions of a coward.”