99% sure that the 2 walls we're taking out are structural but obviously the consequences are grave should we be wrong. Our last remodel had a structural wall but it was anticipated and worked into the design.

What if anything have we overlooked?

The house is a 15 y.o. ranch.

There is a steel I-beam in the basement that runs east/west

The roof line/trusses run north/south.

There are no attic beams that seem to be supporting anything.

Wall 1 (6')runs north/south and has been removed in another like home.

Wall 2 (30") runs perpendicular and adjoins wall 2 (L shaped.

What other items may determine the structural support of a given wall(s)?

Could either of the walls be supporting anything?