Finally great news and sort of bad news

We managed to get in the car after bending the door slightly and putting the key into the ignition. Then jump started it and bang we were in

Now issue is the car as soon i turned the car of, the battery died. I tried turn ignition, it was trying to connect battery but then died out. So something in the car seems to be draining the battery, not sure what and where to even start looking now as this has come out the blue.