Three persons, including two women, were killed and 15-year-old girl was injured on Tuesday when a pit in which they were collecting fly ash caved in at an industrial area on the outskirts of Chhattisgarh`s capital Raipur, a police official said.

The four were extracting a layer of fly ash beneath the earth in the pit at Sankra village under Dharsinwa police station limits when the soil around them collapsed, trapping them under the debris, he said.