Should I Replace the door?

[Lj Pirate]

We are between tenants.  During cleaning I see the back door which is metal with a large window was broken.   The inside pane of double panes of glass was obviously broken.   Shards of glass are visible all around the inside of the window.   In its place is a piece of plexiglass.   It wasn’t noticeable to me until I was cleaning and the tenant never told us about it.  

Would you recommend replacing the window or whole door or leaving it as is?   It looks alright as is but wasn’t sure with it being an exterior door if it would be a safety concern.  

Thank you for any advice!