I have a sentence. I'd like to know the second "that" could be removed?
The accident resulted from an outside sudden cause that the driver had no control and (that) occured without any warning signals, thus the accident was inevitable.
This sentence comes from two separate sentences. The first is: The accident resulted from an outside sudden cause that the driver had no control. The second is: The cause occurred without any warning signals.
I combined the two sentences together, but I am not sure whether the second "that" should be removed or not? I am often confused by this problem; anybody can give me a general rule?