pronunciation of 好莱坞 (Hollywood) ?

Is the last character in 好莱坞(Hollywood) supposed to be read 1st tone or 4th ? Some dictionaries show one and some show the other. 

The reason I want want to ask about this one is, the character 坞(wu) only has one reading in all of the dictionaries I've checked, which is wù, but somehow some dictionaries are showing it Hollywood as hǎoláiwū. 

Can anyone explain this phenomenon?