i'd say if the taser didn't kill her it clearly knocked her the fukk out given her heart issue and then... well they left her in the pool for probably hours. it only takes minutes for your lungs to fill up with water.
i still don't get how they BOTH couldn't force the body in (i've forced some luggage into overheard compartments on airplanes that were in much tighter spaces than that burner looked like), but they were able to drag it around nyc. i get she was probably 130-150 lbs, but even then. he pulled that shyt up some kind of staircase to ground level and cisco aka skinny turtle looks like he's on a diet of adderall and hacking, but couldn't put it in the incinerator.