The accident occured when the three were taking shelter besides a wall during the dust storm in Jamuna Paar area and it collapsed on them killing Abhay Kumar (12), SDM Chandra Vijai Singh said.
The injured, Tilak Singh and Urmila Devi, were rushed to a hospital, Vijai added.
This is the third storm in Mahaban Tahsil area in a fortnight, the SDM added.