Alli and the Ambulance Arrive at Brit's

The following italicized article is from www.tmz.com:

Alli Sims was all smiles when she arrived at the chaotic scene surrounding Britney's -- and had to cover her mouth to block her cheek-splitting grin!

The medical motorcade arrived shortly after -- as a team of motorcycle cops led the way for an ambulance that was later to take Britney to the UCLA Medical Center.

More video on the way ...

Source: TMZ