A NAN correspondent, who visited the scene of the incident on Friday afternoon, learnt that the structure under construction gave way when labourers were putting more concrete on it.
Eye witnesses told NAN that 18 men were working on the building when they noticed some signs of crack which prompted them to flee.
Three of them, however, were unlucky as they collapsed under the falling debris.
One of the witnesses, Hassan Lukman, said the injured men were rushed to the Murtala Muhammed Hospital, Kano, where they were receiving treatment.
A labourer at the site, Tijjani Inuwa, told NAN that the new structure was meant to be a filling station, but could not say whether the materials being used were sub-standard.
Two buildings under construction collapsed in the state capital last year causing injuries to the labourers on site.
Rabi’u Ali, Chairman of the state’s branch of the Nigerian Society of Engineers, had blamed the collapse of one of the buildings at the city centre on the use of sub-standard materials.
He warned that unless the right materials and qualified experts were used in erecting structures, such buildings would always endanger people’s lives.
