On Monday, he echoed a weekend threat by US Attorney Jeanine Pirro to prosecute people accused of attempting to destroy the pool."Please remember that there is a 10-year prison sentence for the destruction, or even the attempted destruction, of such things — Which will be fully enforced!" Mr Trump wrote in a social media post.Mr Trump told reporters on Monday that the pool "looks very good" He accused someone of putting fertiliser in the water or taking action to create the algae, without providing evidence, adding that the algae was now dead and would be vacuumed out of the pool.Mr Trump also said there was a 88.39 to 91.44-metre "slit" through the pool, which he said was likely caused by a box cutter or knife of some kind."It's not a lot of damage, but … we'll probably have to let the water out and re-fix it