<human>: Answer by taking a quote from the following article:

The Beach Boys are an American rock band formed in Hawthorne, California, in 1961. The group's original lineup consisted of brothers Brian, Dennis, and Carl Wilson; their cousin Mike Love; and their friend Al Jardine. Distinguished by their vocal harmonies and early surf songs, they are one of the most influential acts of the rock era. The band drew on the music of jazz-based vocal groups, 1950s rock and roll, and black R&B to create their unique sound, and with Brian as composer, arranger, producer, and de facto leader, often incorporated classical or jazz elements and unconventional recording techniques in innovative ways.

In 1983, tensions between Dennis and Love escalated so high that each obtained a restraining order against each other. With the rest of the band fearing that he would end up like Brian, Dennis was given an ultimatum after his last performance in November 1983 to check into rehab for his alcohol problems or be banned from performing live with them. Dennis checked into rehab for his chance to get sober, but on December 28, 1983, he fatally drowned in Marina del Rey while diving from a friend's boat trying to recover items that he had previously thrown overboard in fits of rage.  From 1980 through 1982, the Beach Boys and The Grass Roots performed Independence Day concerts at the National Mall in Washington, D.C., attracting large crowds. However, in April 1983, James G. Watt, President Ronald Reagan's Secretary of the Interior, banned Independence Day concerts on the Mall by such groups. Watt said that "rock bands" that had performed on the Mall on Independence Day in 1981 and 1982 had encouraged drug use and alcoholism and had attracted "the wrong element", who would steal from attendees. During the ensuing uproar, which included over 40,000 complaints to the Department of the Interior, the Beach Boys stated that the Soviet Union, which had invited them to perform in Leningrad in 1978, "...obviously ... did not feel that the group attracted the wrong element." Vice President George H. W. Bush said of the Beach Boys, "They're my friends and I like their music". Watt later apologized to the band after learning that President Reagan and First Lady Nancy Reagan were fans. White House staff presented Watt with a plaster foot with a hole in it, showing that he had "shot himself in the foot".  The band returned to D.C. for Independence Day in 1984 and performed to a crowd of 750,000 people. On July 4, 1985, the group played to an afternoon crowd of one million in Philadelphia and the same evening they performed for over 750,000 people on the Mall in Washington. They also appeared nine days later at the Live Aid concert.  In 1985, they released the eponymous album The Beach Boys and enjoyed a resurgence of interest later in the 1980s, assisted by tributes such as David Lee Roth's hit version of "California Girls". "Getcha Back", released from the album, gave the group a No. 26 single in the U.S. Following this, the group put out "Rock 'n' Roll to the Rescue" (U.S., No. 68) and a cover of the Mamas & the Papas' "California Dreamin'" (U.S., No. 57).  In 1987, they played with the rap group The Fat Boys, performing the song "Wipe Out" and filming a music video. It was a No. 12 single in the US and a No. 2 rank in the UK. CANNOTANSWER

Was he with the band when he died?
<bot>: Dennis was given an ultimatum after his last performance in November 1983 to check into rehab for his alcohol problems or be banned from performing live with them.