Two custodians were fatally shot inside Mark Twain Elementary School in Garfield Ridge on Monday afternoon in an apparent murder-suicide, according to preliminary police radio transmissions.According to a statement from Chicago police, a 63-year-old man and 48-year-old woman were each found with a s ingle gunshot wound to their heads inside the school in the 5100 block of South Lotus Avenue at 3:40 p.m. Both were taken to Christ Medical Center, where they were pronounced dead, police said. A weapon was recovered at the scene, police said.According to police radio transmissions, a dispatcher said the shooting stemmed from a disagreement between two custodians. Both people were found inside Mark Twain Elementary School, according to the radio dispatches. One of them was found inside the school's lunchroom, the dispatcher said.Both of the gunshot victims were custodians, according to Eric Bailey, spokesperson for SEIU Local 73, which represents custodians at Chicago Public Schools. No students were at the school, as classes don't begin there until Aug. 24.Trumaine Reeves, executive vice president of SEIU Local 73, said in an emailed statement that the "only facts we know right now are that two families have lost a loved one and our prayers are with their families, and the staff, students, and families at Mark Twain Elementary School."Chicago Public Schools did not immediately answer a request for comment.A neighbor who lives across from the school told the Sun-Times she saw first responders remove the bodies of a man, then a woman, from inside the school. The emergency response initially included four fire trucks and four ambulances, according to the woman, who asked not to share her name.Several police officers and detectives could be seen in and outside the school Monday evening.Additional information was not immediately released. ...read more read less