House burnt down. The next year I sold the land at a gain. No Form 1099-S was received. Can I reduce the new house basis or is this taxable gain?

Edited 3/11/18

The sale of the land would generally be a gain but see further answers below. Your house that was burnt by file should have been reported as a Casualty and Theft to recoup any amount that the insurance company did not reimburse.

I don't understand your answer on the land gain?  Is it taxable and where do I report the gain?  Or, do I reduce the basis in the new house?

Edited. It may be an optionsince the house/land would generally be valued together.You do not reduce the basis of the new house. The two properties have nothing to do with each other.

If no 1099-S was issued was this your personal residence prior to the fire ?   If so did you profit more than $250K ($500K married) ?  And did you live in the home for more than 2 years out of the last 5 prior to the sale?

This was my personal residence prior to the fire.  The profit was less than $500,000.  Yes we lived in the house 30 years before the fire.

Then you have nothing to report on a tax return.  What you did with the proceeds of the home is not material, has not been for more than 20 years.