The Doctor was looking at them "a cart blew up," He told them. He was rather frustrated and worried for his friends. He didn't think the engineer was doing a good job trying to get them down.
He wondered what was even going on, he didn't get why they would let people ride it, if there was a problem. He was looking around. Think Think.
It was quite a dangerous thing for them to be stuck. He wanted to make sure that he could get them down soon as he could.