I'm so sorry!
Snake keeping is an experience wether it be negitive or positive, you pull through the negitive to get to the positive, and the positive is the most rewarding, you also learning better from your own experiences. Snakes are wonderful pets, please dont let this discourage you from keeping snakes, just learn from this experience and like Bitsy said, go over your viv with a fine tooth comb, figure out whats wrong with the viv, ( holes,spaces etc. ) and fix them, always remember to put your lid and locks back on, you'd be superised how much a snake can lift, dont just rely on books for a rock to hold the tank's lid on, get proper locks, besides making sure the magician's cant get out of the tank, your good to go!
Again Good Luck In The Near Future I Hope, keep us posted, and again I'm really sorry for your loss!!