Sad day in my house today... my "Lion" tank crashed... :cry

Those of you that were here at the last meeting may have seen my beautiful Lion fish... I lost my favorite one of all time My Radiata :cry the Volitan, and what appears to be now both my fuzzy Dwarfs all in a matter of 4 days... I don't know what could have happened...
nothing new in that tank..nothing different..same feeding pattern...

them first one to die was the Volitan... i did a Major water change after that and then 2 days later the Radiata died, then a mini water change and last nite the fuzzy dwarf and now i cannot find the 2nd fuzzy dwarf.. the ONLY survivor was Erik's Volitan thats been taken out of the tank already and my porc puffer, both tangs and my snowflake...

Im really puzzled as to what could have gone wrong so fast?
the last test was about 2 weeks ago and nothing was off the chart.. water parameters were ALL normal and i test everything...
Ive tested the water again today AFTER all the deaths and my nitrates are OFF THE CHART...

i have no place else to put the remaining fish...
Right now i cannot take care of this tank because my dad is sick and in the hospital, i dont have a quarentine tank and i dont want to get my clowns that are in the 58 sick... if anyone out there has a "hospital tank" that can hold my Porc puffer at least i will pay for room and board.. :( i'd hate to see him suffer.. I'll just pray that my snowflake makes it till i get a chance to do another Major water change first chance i get...

let me know

thanks
Thelma