Please be safe when under your TJ Sad News

yikes. I always use jack stands AND put the removed tires/wheels under the belly skid , but even that makes me nervous in the front end with all the weight.

I about crapped my pants last night when I was cycling my suspension and the axle slipped off the jack. A dana 30 wouldn't be as likely to kill as long as it didn't land on your melon, but I still took a couple minutes to gather my thoughts before getting out the ratchet strap and starting to work on getting the jack out from between the axle tube and tie rod.
 
Very sorry to read this. Thoughts to family and friends.
Years ago a friends car broke down on the side of the road. He had the OEM jack, but happen to have jack stands. Except he was in sand and while under the car, the jacks sank and shifted, dropping the frame on his head. Lucky for him a trooper pulled up moments later and was able to save him.