Is there an equivalent to "awww" in English for expressing sympathy? Just now, I was talking to someone on WeChat and he mentioned how he got caught out in the rain.  I wanted to say "awww" out of sympathy as we do in English, but I don't know how to.  The closest I know is 啊 (a) = "ah" or 噢 (ō) = "oh", "oops" which don't really suit the situation.

Question: Is there an equivalent to "awww" in English for expressing sympathy?

Searching for awww in YouDao suggests 噢, such as 噢谢谢你, but I don't think this is the same as sympathy (although maybe I'm wrong).  Other searches (aww (dict.cn) aww (YouDao)) don't really help.
Usually 哎, 咳, 唉, those means "sigh", can not find more appropriate words.
or 哎呀, but it sounds affected when you read it, more natural in speaking.