Flooded Basement - Hoarder House - Great ARV

[Shenelle Keisha Smith]

Hi everyone! I'm a brand new investor working on my first deal (NYC Queens based). I found a home while I was driving and the "owner" is willing to sell. Both of her parents have died and left the home to her and her brother. All but one of the windows is boarded up but, from the outside, the house looks otherwise to be a solid flip. When I went inside to tour the property (3 BR 2.5 bath), I saw that she's a hoarder. There are clear walkways, narrow, but cleared enough, but 2/3 rooms are inaccessible due to the hoard. There's no electricity and no running water I believe; she doesn't know for sure about the water but doesn't think so; she uses diapers and urinates in bottles which I saw in various places throughout the home. The bathroom is a biohazard so I couldn't check and failed to open the kitchen faucet. She told me there was also a fire in the basement and -- here's the big issue -- the basement is completely flooded and inaccessible and you can hear water running! Unfortunately, there is a mortgage on the property, but the heir doesn't know how much (she didn't know whether or not there was a mortgage on the home or not!), propstream says $321K. ARV $650K. As a new investor, I'd take out hard money for this but don't know if I should run for the hills or not. Please help.