Like any concrete structure, a hatchway entrance will begin to form cracks over time. Water will flood through these cracks, move to the stairs and end up flooding into your basement area.
Some old-fashioned hatchway doors were built with loose panels of wood (instead of metal), with little or no attempt to keep water out. Water easily floods through the gaps in these doors.
Once water builds up in a hatchway entrance, the puddles will expand into the basement.