If the glass is laminated safety glass, there isn't any safety issue with the crack,it will just look unsightly. If it's ordinary annealed glass get it replaced professionally ASAP. Cracks like this cannot be repaired and if it's annealed glass it's dangerous,especially where human traffic is involved.
I've had 30 years in the glass industry and seen injuries caused by this problem not being attended to promptly and PROPERLY! Please get it checked out soon.
Grum Grummer
June 2009