Brooklyn celebrated the late, intensely great Beastie Boy Adam Yauch with MCA Day over the weekend. (Yauch’s stage name was MCA.) The event drew an enormous crowd of fans and friends and earned a write-up on RollingStone.com. Well, the brains behind the celebration hails from the Bay State. Mike Kearney, 33, grew up in Weymouth. Seems he planned the first MCA Day a year ago after the rap star died of cancer. “My brother had texted me about it,” Kearney told us, referring to Yauch’s death. “I was just staring at the screen. I was numb.” His coping mechanism was to choose a spot in MCA’s native Brooklyn for a gathering and then spread the word to the Beastie Boys’ many fans. (Supporters last year included MCA’s bandmate Ad Rock — a.k.a. Adam Horovitz — who showed up to dance and play the entire Beasties catalog.) Kearney’s second annual party was even bigger. His MCA Day bash drew hundreds of fans, including former Beastie Boy cohort DJ Hurricane, Daniel O’Connor (“Danny Boy” from House of Pain), and New York state Senator Daniel Squadron. Kearney said the event also included messages of peace in keeping with Yauch’s activism for Tibet. “It was very Beastie,” he said.