High risk
The glass has gone through: there is a hole, shards in the frame, and glass on the floor.
The glass is out and you need the opening secure tonight, before any replacement glass can arrive.
Caution
A crack runs across the pane and nobody hit it, or a small chip has grown into a line since last week.
The angled fillet of putty holding the glass into a timber window has cracked, gone chalky, or fallen out in pieces.
A leaded panel has bowed outwards, a small pane has cracked, or the panel rattles and leaks air.
A shower screen, table top, balustrade or door pane has exploded into thousands of small granules with nothing touching it.
Panes have blown out of the greenhouse or cracked, and there is broken glass around the frame and in the border.
The pane in a front, back or internal door has cracked, and the door still gets used every day.
You want a cat flap in a glazed door or window and have been told the glass cannot simply be drilled.
A glass or polycarbonate roof panel has crept down the rafter, leaving a gap at the ridge and water coming in.
Describe the job and get a fixed price from a local glazier.