A father was killed and his two children were injured when a grenade detonated at their Indiana home on Saturday, according to authorities.

The Lake County Sheriff’s Department responded to the home in the 3400 block of W. Lakeshore Drive around 6:30 p.m. for a reported explosion.

The family was going through a grandfather’s belongings at the northwest Indiana home when they found a hand grenade. The device detonated when someone reportedly pulled his pin, the sheriff’s department says.

The father was found unconscious at the scene and later pronounced dead. His two children, a 17-year-old boy and an 18-year-old woman, were taken to a local hospital with shrapnel wounds.

The Porter County Bomb Squad responded to the area to secure it and determine if there were any other explosive devices, according to the sheriff’s department.

The Lake County Sheriff’s Department continues to investigate this incident.