London - "Smells like lobster gumbo during advanced putrefaction," worried Royal Parks Agency sources admitted today.
By lunchtime hundreds of London sunbathers had been taken in droves to A&E as noxious fumes continued to spew from the tragic, near derelict water feature.
Fermenting dog turds, Dutch elm diseased-leaves and a bumper crop of spent condoms have seen the shallow Hyde Park gutter give off record amounts of brain-damaging gases.
This morning's soaring temperatures were already playing havoc with the commuting public amid London Transport warnings that radiators on buses and underground trains 'cannot be switched off just because of a whim'.
Hapless commuters travelling past Hyde Park Corner were subjected to the additional 'treat' of fiendish fumes wafting in through buses' miniscule open windows - likened by some to the Nazis' lethal Zyklon-B in World War II concentration camps.
"About time this hideous fountain was concreted over," disgusted No 19 route bus user Hildegarde Higgs-Boson, 74, told TV news reporters.
"Wanna see pix of me in my polka dot bathing costume?"