Authorities are investigating the death of a 9-month-old infant who was fatally shot by his 5-year-old brother in northwest Missouri on Monday morning. The tragic incident took place in the rural town of Elmo Monday morning when a little boy accidentally shot his baby brother with a .22 caliber Magnum revolver.

Sheriff Darren White said the infant's mother called 911 from her home in the 100 block of South Scott Street following the shooting around 9 a.m., according to KCTV 5 News.

"She said that she needed an ambulance at her home, that her 5-year-old son had shot her 9-month-old son in the head with a paintball gun," White said.

However, after arriving on the scene, emergency crews determined that the child had been shot in the head with a real gun.

The baby was then flown to Children's Mercy Hospital in Kansas City, where he was pronounced dead three hours later.

According to officials, the infant was in a playpen when the older child found a loaded handgun lying nearby. The Nodaway County Sheriff's Office says the gun was not owned by the mother and belonged to another family member.

"You know, just some gun safety could have cone into play, and would have maybe, you know prevented the situation, but it's just really sad, altogether," said neighbor Jessica Hutchison to KCTV.

Kathy Armentrout, a neighbor and friend of the family, told fox4kc.com the woman was alone with her four sons when the shooting took place.

"They're a very good family, and this was a tragedy. I just hope everybody prays for them," she said.

Deputies do not suspect that foul play was a factor in the incident and think the shooting was an accident. Police are investigating how the child managed to get hold of the gun.

In the meantime, the three surviving children were placed in the custody of relatives during the investigation.