Authorities said a seven-year-old boy is in critical condition after he was shot by his grandmother who mistook him for an intruder.

According to WTSP, Linda Maddox of Tampa and her grandsons were sleeping in a room after the boys' father had left for work on Tuesday morning. The 63-year-old woman told Hillsborough County Sheriff's deputies that she propped a chair under the door handle for extra security.

Around 1 a.m., she heard that chair skid across the floor. Assuming it was an intruder, the grandmother grabbed the .22 caliber pistol she keeps by her bedside and fired a single shot into the darkness.

The Associated Press noted that Maddox then heard the cries of her young grandson, Tyler, who went to the ground screaming. The bullet struck the boy in the upper body. Paramedics arrived and transported him to a local hospital where he is listed in critical, but stable condition.

There has been no immediate word of any charges against the grandmother.