The labourers were engaged in work on the fourth floor of the building of an ayurvedic college, about 20 km from here, when the mishap occured, police and fire brigade sources said.
Fire brigade personnel were successful in rescuing one of the workers trapped under the debris.
Police said they were investigating the quality of construction materials, after which a case would be filed against the persons responsible.
Most of the victims were reportedly contract labourers from outside Maharashtra, police said.