Three employees were killed during an apparent robbery attempt at a McDonald's restaurant, about 2 miles from another fast-food restaurant where two workers were killed last month.
A fourth employee was in critical condition Monday with stab wounds.
Police received a 911 call just after midnight from the restaurant in suburban Hermitage, but the line went dead. An officer sent to investigate looked through a window and saw a trail of blood.
"Because all of the doors to the restaurant were locked, the officer used her baton to smash out the glass in one of the doors and entered the building," said Don Aaron, a police spokesman.
Officer Tracy Holmes found three workers shot and lying close to one another in the rear of the restaurant. The stabbing victim was near the telephone.
Police said money appeared to have been taken from the restaurant. No arrests had been made. Authorities were seeking a car that was seen leaving the restaurant around midnight.
The McDonald's, which had closed at 11 p.m., is about 2 miles east of a Captain D's restaurant where two employees were shot to death Feb. 16.