Then, guests from the wedding of Sannuti and Michael Sofka who were staying at the hotel returned to the Sheraton after a reception elsewhere and proceeded to the hotel bar, where they got into a fight with guests from the first wedding, police said.
Sannuti and Sofka both attended St. Joseph's University and live in Jersey City, according to their LinkedIn pages and other online records. Sofka, 29, works as a business-development associate at Newtown Capital Management, and Sannuti, 28, is a vice president of asset management HR at Credit Suisse.
Sannuti's page on Pinterest shows that she'd been contemplating a wedding with elements of love and beauty, not of violence and death. Photos on the page include a love message from the groom to the bride on her wedding shoe, flowers glued to Styrofoam balls, and the palms of four hands displaying the word F-O-R-E-V-E-R, spelled out in Scrabble tiles and a wedding band for the letter O.
Lt. Ray Evers, police spokesman, said it's still not clear what sparked the fights.
"I don't have a solid answer how it started," he said, "but we had to come in and clean it up."
Hotel guests said that between 50 and 100 cops showed up and tried to keep the peace but that several partygoers fought back.
The YouTube video shows one cop hitting a combative guest three times with a baton. Evers said police also fired a stun gun at that man, identified as Matthew Sofka, when he resisted arrest.
Sofka, 26, a relative of Michael Sofka's, was taken into custody and charged with assault on police, inciting a riot and related offenses, Evers said.
On his Facebook page, Sofka, of Westfield, Union County, N.J., lists "The Hangover Part II" and Bud Light among his "likes."
Two other men, both in their late 20s, were given summary citations for disorderly conduct. Their names had not been released as of Monday night.
Police said more arrests were expected as they interview more guests and responding police officers, and as they pore over additional surveillance footage.
Outside the hotel after the fracas, Sannuti's uncle Vincent Sannuti, 57, suffered a heart attack, authorities said. He was taken to Thomas Jefferson University Hospital, where he was pronounced dead at 2:51 a.m. Sunday.
One of Vincent Sannuti's neighbors, who asked not to be identified, said Sannuti was a father of four and "one of the nicest people you could ever meet."
"What a father! He was just outstanding," she said. "He was extremely nice and compassionate and an excellent neighbor.
"My mom always said, 'You need one good neighbor,' Well, Vince was that guy," she said. "We were really upset to hear about what happened."
Sannuti's son Vincent, who, along with his brother Nicholas, own a Philly-themed apparel company called Aphillyated, took to Twitter on Monday to mourn their father.
"R.I.P. Dad," he wrote. "You taught me everything. I Love You So Much Vito."
The Sannuti-Sofka wedding reception was held earlier in the evening at Vie, on Broad Street near Green.
Family members of the bride and groom declined to comment. Names of members of the second wedding party involved in the fight have not been released.
Contact Stephanie Farr at farrs@phillynews.com or 215-854-4225. Follow her on Twitter @FarFarrAway. Read her blog at PhillyConfidential.com.