( CNN ) -- Frank Lautenberg , a New Jersey Democrat associated with major legislative achievements over five terms in the U.S. Senate and the chamber 's last surviving World War II veteran , died on Monday of viral pneumonia , his office said . Lautenberg , 89 , missed key Senate votes late last year during a weeks-long absence because of a cold that turned into what he called a `` severe case of bronchitis with fluid in the chest . '' He also battled stomach cancer in recent years . He announced in a statement in February that he would not seek re-election next year , but he continued to push for stronger gun control laws . After last month 's Boston Marathon bombings , Lautenberg said he would reintroduce legislation to require background checks for sales of explosive powder . An influential businessman-turned-legislator , Lautenberg scored big victories in Congress , including a ban on smoking on airplanes , preventing domestic abusers from possessing guns , cracking down on drunken driving , and the `` Toxic Right to Know '' law about the release of pollutants into communities . `` Frank Lautenberg has been one of the most productive senators in the history of this country , '' Senate Majority Leader Harry Reid , D-Nevada , said in December 2011 on the occasion of Lautenberg 's 9,000th vote , the statement by Lautenberg 's office said . On Monday , political colleagues and foes lauded Lautenberg as a passionate advocate for the issues he championed . Lautenberg : The last 'swamp dog ' `` He improved the lives of countless Americans with his commitment to our nation 's health and safety , from improving our public transportation to protecting citizens from gun violence to ensuring that members of our military and their families get the care they deserve , '' said a statement by President Barack Obama , a former senator . Secretary of State John Kerry , in remarks to reporters , called his longtime fellow Democratic senator `` tenacious as a legislator '' and someone who `` never forgot where he came from . '' In particular , Kerry cited Lautenberg 's advocacy for environmental issues and his spirited defense of Kerry 's military record when it came under attack by Republicans in the 2004 presidential election campaign . `` He was as loyal as he was patriotic , '' Kerry said , also noting how `` during the years when Frank was going through chemotherapy and he was weakened by cancer , he was still down there on the floor of the United States Senate floor fighting on every environmental debate late into the night . '' New Jersey 's Republican governor , Chris Christie , told a GOP event on Monday that he often disagreed politically with Lautenberg , but he respected the senator 's battling spirit . `` We had some good fights over our time -- battles on philosophy and the role of government , '' Christie said . `` I think the best way to describe Frank Lautenberg and the way he would probably want to be described to all of you today is as a fighter . Senator Lautenberg fought for the things he believed in and sometimes he just fought because he liked to . '' Lautenberg leaves tricky political question for Christie . According to New Jersey law , Christie can appoint a temporary replacement to serve until a special election in November or fill the rest of Lautenberg 's term , which expires next year . With the likelihood that Christie will appoint a Republican , the Democratic majority in the 100-member Senate would decrease to 52 , along with two independents who caucus with the Democrats . Possible GOP appointees would include state Sens . Thomas Kean Jr. and Joe Kyrillos , a Christie ally who lost to Democrat Bob Menendez in the Senate race last year ; Lt Gov . Kim Guadagno , and Assembly Republican Leader Jon Bramnick . On the Democratic side , Newark Mayor Cory Booker announced in January he intended to run for the Senate next year , which caused a public tiff with Lautenberg , who later decided against seeking re-election . The son of Russian and Polish immigrants , Lautenberg grew up in Paterson , New Jersey , and enlisted in the military at 18 , his office said . He was a member of the United States Army Signal Corps from 1942 to 1946 , according to his biography . After the military , he graduated from Columbia University with the help of the GI Bill , then joined with two boyhood friends to start payroll processing firm Automatic Data Processing , or ADP , which grew into one of the world 's largest computing services companies . Lautenberg was first elected to the Senate in 1982 and won re-election twice . He did not seek re-election in 2000 when his third term expired , but was recruited to run again two years later after Democratic Sen. Robert Torricelli quit his re-election bid weeks before the polls opened amid reports of ethical issues . Lautenberg was then re-elected in 2008 . Survivors include his wife , Bonnie Englebardt Lautenberg ; six children ; and 13 grandchildren , the office statement said . People we lost in 2013 : The lives they lived . CNN 's Tom Cohen , Peter Hamby , Susan Candiotti , Robert Yoon and Paul Steinhauser contributed to this report .
Political friends and foes describe Frank ##en as a fighter . Lautenberg was a strong advocate for tougher gun laws . The New Jersey Democrat was the last World War II veteran in the Senate . Gov . Chris Christie permitted under ##lings to appoint temporary senators .