An 80-year-old woman in a wheelchair was wounded in the head by a potentially accidental firing of a gun inside a house late Tuesday afternoon in the city’s Cedarbrook section, police said.

The shooting happened shortly after 4 p.m. on the 2300 block of 77th Avenue. The woman and her adult daughter were on the first floor and three 18-year-old men, including the woman’s grandson, were upstairs when a gun discharged through the floor and struck the woman, said police Capt. John Walker.

The woman was taken by medics to Einstein Medical Center, where she was listed in stable condition with a bullet lodged in the back of her skull, Walker said.

The grandson and another man remained at the scene and were detained for questioning, Walker said. The whereabouts of the third man was unknown.

It was not immediately known who fired the gun, Walker said.