A father was killed and his two teenage sons were injured after a hand grenade exploded inside their northwestern Indiana home, authorities said.

The family members were going through a grandfather's belongings Saturday evening when they found the device, Lake County Sheriff's Office spokesperson Pam Jones said in a news release.

"Someone reportedly pulled the pin on the device, and it detonated," the release read.

Sheriff's deputies responded to the home around 6:30 p.m. and found the father unresponsive. He was later declared dead.

The two sons, ages 14 and 18, were taken to an area hospital with shrapnel wounds, according to the sheriff's office.

The explosion happened in the community of Lakes of the Four Seasons, Indiana, approximately 50 miles southeast of Chicago.

"The Porter County Bomb Squad was called to secure the area and determine whether there may be additional explosive devices," the release read.

Authorities are currently investigating, according to the release.