What to say to a friend thats had a miscarriage

We are off to see my hubbies best friend and his wife next week. About 2 weeks ago she miscarried their triplets at 12 weeks.

For those of you that have miscarried, was there something a friend said or did that helped you through it? Hubby has been there to visit and help them but my first trip up will be next week.

I feel like I want/should do something more than just being a shoulder to lean on