Law enforcement officials in Lake County, Indiana, said a man was killed, and his two teenaged children were injured after a live grenade in a grandfather's belongings detonated.

The Lake County Sheriff’s Department said officers responded to reports of an explosion in Lake of the Four Seasons at about 6:30 p.m. on Saturday.

Investigators learned that a family was going through a grandfather’s belongings at a home on Lakeshore Drive when they found a grenade.

Sign of location near Indiana grenade explosion

An Indiana man was killed and his two children injured when someone pulled the pin on a grenade that was found in a grandfather's belongings.  (Fox 32 Chicago)

Someone then pulled the pin from the grenade, and it exploded.

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When police arrived, a 47-year-old man, later identified as Bryan Niedert of Lake of Four Seasons, was found unresponsive and later died.

A field near where the grenade exploded in Indiana

The Lake County Sheriff's Department said someone pulled the pin out of the grenade.  (Fox 32 Chicago)

His two children, an 18-year-old female and 14-year-old male, were taken to a nearby hospital to be treated for shrapnel wounds.

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Porter County, a neighboring county, sent its bomb squad to the scene to help secure the area and determine whether any additional explosives were inside the home.

A building near where the grenade was found

The father and his two kids were looking through a grandparent's belongings when they found the grenade.  (Fox 32 Chicago)

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The investigation into the incident is being conducted by Lake County Sheriff’s Department Homicide detectives and crime scene investigation unit.