No one knows for certain what happened, but it's a fair bet that it was not an accident.
没有人知道究竟发生了什么,但几乎可以肯定这并非意外。
since her parents had impressed upon her that it would be unforgivable to miss it and cause the friends with whom she was going to stay to make two journeys to meet her.
因为她的父母再三跟她说,如果误了这趟车,她的东道主朋友就得接她两趟,这是不应该的。