Gwen Stefani took her sons Kingston and Zuma to the Botanical Gardens in San Marino, near LA, on Saturday. Her littlest one, Zuma, was sporting a new accessory — his arm was in a cast after a recent fall at their home! Gavin Rossdale missed out on the family fun because he was off performing at a party in Las Vegas. Gavin spoke about Zuma's fall before heading inside the bash. He said, "It was one of the worst nights of our lives. . . It was one of those freak events — he fell. A freak accident. . . . The kids are never alone and you turn your back — it takes a split second." Zuma seemed to be in good spirits despite the accident, as he got pushed in a stroller by his attentive older brother Kingston on the way toward the gardens with mom Gwen.