At around 1.30 PM, the front portion and balcony of the already dilapidated building crashed at Achole village in Nallasopara, they said.
While the building was empty as it had earlier been declared unsafe, a portion of it collapsed on two pedestrians who were walking by, killing one of them.
The deceased was identified as Rajesh Prajapati (38), police said, adding that the injured person was admitted to a local hospital.