What ghost story is true behind the cracked marble in Delta Bessborough?

Keeping with the haunted hotel theme for #HauntedSKHumpday, I was trying to find out what actually caused the cracked marble in the stairwell of the Delta Bessborough in Saskatoon. However, I found two ghost stories with two different theories... which one do you think is true? The bus boy who fell down the stairs, and that can still be seen ...