Someone called 911 at about 1:30 a.m. and said a woman in Super Wash'n Dry at 1460 S. 43rd St. started acting erratically. The witness said the woman pulled out a razor blade and threatened to kill anyone who came near her.
By the time police arrived at the business, the woman had left the laundry and was sitting in her car.
Officers took her into custody on suspicion of making criminal threats with a weapon.
Police did not say if the woman appeared to be under the influence of drugs or alcohol or if she had a history of mental problems.