• The two teens were taken to hospital after suffering shrapnel wounds
  • The identities of the teens weren't released by authorities
  • People are urged to call 911 if they find any explosive devices at their home

A father was killed, and his two teenage children injured after a hand grenade found in the grandfather's belongings detonated in their Indiana home.

The Lake County Sheriff's Department responded to the house in the gated community of Lakes of the Four Seasons on W. Lakeshore Drive around 6.30 p.m. Saturday on reports of an explosion.

The family members were looking through their grandfather's belongings at their home when they found a hand grenade among his things. The sheriff's department said that the device detonated when someone accidentally pulled the pin, CBS News reported.

"Someone reportedly pulled the pin on the device and it detonated," Sheriff Oscar Martinez Jr. said in a statement, according to NPR.

When the police reached the house, they found the father, identified as Bryan Niedert, 47, unresponsive. He was later pronounced dead. His two children, a 14-year-old boy and an 18-year-old woman, were taken to an area hospital after they suffered shrapnel wounds. The identities of the two teens weren't released by authorities.

The Porter County Bomb Squad also responded to secure the grenade and determine if there were any other explosive devices at the scene.

The sheriff's department homicide detectives and crime scene unit launched an investigation into the matter. "Injuries, cause and manner of death are all pending," the statement said.

Detectives were "looking into whether the device may have self-detonated due to its age or other factors, whether the pin was pulled or whether any other circumstance may have been involved," according to NBC Chicago.

The coroner's office said an autopsy on the father's remains would be performed Monday.

Meanwhile, authorities urged people to immediately call 911 if they find a grenade or other explosive ordinance at their residence.

An FBI report from last April suggested it was not uncommon for families to find decades-old explosives in war veterans' belongings. Several service members either brought the devices home from their combat service or purchased them later.

"Most of the devices found today come from World War I (which the U.S. entered 105 years ago this month), World War II, Korea, Vietnam, or the Gulf War," the report added.

The FBI further warned these devices can remain intact for decades, but explode without notice, considering their military ordinance.

"They are highly dangerous, and only a trained bomb technician should handle them," the report added. "We'd much rather come take a look at it and have it be nothing. We don't want anyone to get hurt."

Representation. A grenade. njellL/Pixabay