ST. LOUIS (AP) -- The bacteria that causes Legionnaires' disease was found in rooms of a hotel in a popular Missouri tourist town associated with Mark Twain, and health officials said Tuesday that one of three people who contracted the disease after staying there has died.

Missouri health officials and the U.S. Centers for Disease Control and Prevention launched an investigation last month of the Best Western on the River Hotel in Hannibal. The hotel sits a block from the home where Mark Twain spent his childhood, and sites connected to the author attract about 500,000 visitors to Hannibal each year.

The CDC took 40 samples on Nov. 10. Samples from four rooms tested positive for Legionella bacteria, said Ryan Hobart, spokesman for the Missouri Department of Health and Senior Services. What caused the bacteria remains under investigation.

Look back at a history of Legionnaires' outbreaks:

4 PHOTOS History of Legionnaires outbreaks See Gallery Legionnaires' disease bacteria found at hotel; 1 guest died Colorized photo of the legionella bacteria under microscope. Following steps played by Rouge Valley Centenary Hospital in recent legionnaires disease at Seven Oaks Home for the Aged. (Photo by Ron Bull/Toronto Star via Getty Images) DROCOURT, FRANCE: Doctor Ramin Roboubi, chief of the Pneumology service at the Henin-Beaumont poly-clinic, looks at the x-ray of a patient suffering from Legionnaires' disease 31 December 2003. Twenty patients out of the 50 registered have been treated in this clinic. Ten are still hospitalized. (AFP PHOTO / PHILIPPE HUGUEN) Illustrated postcard shows the Bellevue-Stratford Hotel, Philadelphia, Pennsylvania, early 1900s. In 1976, the hotel was the site of the first outbreak of the previously unknown and deadly Legionnaires' disease. (Photo by Vintage Images/Getty Images) Up Next See Gallery Discover More Like This HIDE CAPTION SHOW CAPTION of SEE ALL BACK TO SLIDE

Hobart said all three people who became ill had stayed at the hotel over the previous eight months. One of them died. Hobart said he could not provide information about whether the death was specifically due to the respiratory illness or give any information about that person.

Hannibal, in northeast Missouri, is about 20 miles down the Mississippi River from Quincy, Illinois, where an outbreak of Legionnaires' disease occurred earlier this year at the Illinois Veterans Home, contributing to 12 deaths and sickening dozens more.

The illness is a type of pneumonia caused by bacteria that infect the lungs. Named after a 1976 outbreak among participants of an American Legion convention in Philadelphia, the disease can cause coughs, breathing trouble, fever and muscle aches, and death in extreme cases. People can get sick if they inhale mist or vapor from contaminated water systems, hot tubs and other typical sources.

Information on the U.S. Occupational Safety & Health Administration website said about 25,000 cases of Legionnaires' disease occur annually, with more than 4,000 deaths.

The Hannibal hotel consists of two buildings - an older structure, and one completed just this year. Hobart said the new wing of the hotel was not yet in operation when the outbreak occurred. It was inspected as a precaution and no problems were found. That building is open for guests.

The older structure remains closed. The Hannibal Courier-Post reported that papers taped to the hotel's main entrance advised that it was shut for "renovations." A man answering the phone at the hotel hung up on a reporter who called.

Hobart said hotel management has been cooperative. He said remedies will involve "superheating and/or hyper-chlorination of the facility's potable water system." It was unclear when the hotel building would be allowed to reopen.

Related: Photos from the Legionnaires' outbreak earlier this year in New York City:

11 PHOTOS Legionnaires in NYC See Gallery Legionnaires' disease bacteria found at hotel; 1 guest died NEW YORK, NY - AUGUST 13: The Opera House Hotel at 436 East 149th Street, which houses a water cooling tower that was found to have traces of legionella pneumophila bacteria, which may have helped cause the recent outbreak of Legionnaires' disease in the Bronx, is seen on August 13, 2015 in the Bronx borough of New York City. In a press conference today New York City Mayor Bill de Blasio said that while new cases of Legionnaires' may appear, the outbreak has been contained and that the water cooling towers the New York City Department of Health believe are responsible for the outbreak have been decontaminated. (Photo by Andrew Burton/Getty Images) Marvin Montgomery, a Legionnaires disease patient at Harlem Hospital on Thursday, August 6, 2015 in New Yrok, N.Y. Montgomery worked near Lincoln Hospital, one of five sites that tested positive for the bacteria, and frequently used the hospital bathroom. City officials released new numbers Thursday showing the death toll since July 12 was now in the double digits while overall cases had climbed to 100. All the people affected are from the South Bronx. (Photo By: James Keivom/NY Daily News via Getty Images) NEW YORK, NY - AUGUST 06: The Opera House Hotel is viewed in an area of the Bronx which is the center of the outbreak Legionnaires disease on August 6, 2015 in New York City. It is believed that cooling towers in the area contributed to the illness which is believed to be contracted by inhaling mists from contaminated bacteria in the water source. The Bronx, and specifically the area around the Opera Hotel on East 149th Street, is in the middle of the largest outbreak of Legionnaires disease in New York City's history. New York authorities announced that as of Wednesday night the illness has now sickened nearly 100 people since July 10, with at least eight people having died. (Photo by Spencer Platt/Getty Images) NEW YORK, NY - AUGUST 06: A man looks in the window of a building for a person who lost a relative to Legionnaires disease in an area of the Bronx which is the center of the outbreak on August 6, 2015 in New York City. It is believed that cooling towers in the area contributed to the illness which is believed to be contracted by inhaling mists from contaminated bacteria in the water source. The Bronx, and specifically the area around the Opera Hotel on East 149th Street, is in the middle of the largest outbreak of Legionnaires disease in New York City's history. New York authorities announced that as of Wednesday night the illness has now sickened nearly 100 people since July 10, with at least eight people having died. (Photo by Spencer Platt/Getty Images) NEW YORK, NY - AUGUST 06: People walk in an area of the Bronx which is the center of the outbreak Legionnaires disease on August 6, 2015 in New York City. It is believed that cooling towers in the area contributed to the illness which is believed to be contracted by inhaling mists from contaminated bacteria in the water source. The Bronx, and specifically the area around the Opera Hotel on East 149th Street, is in the middle of the largest outbreak of Legionnaires disease in New York City's history. New York authorities announced that as of Wednesday night the illness has now sickened nearly 100 people since July 10, with at least eight people having died. (Photo by Spencer Platt/Getty Images) NEW YORK, NY - AUGUST 06: Lydia Ramirez, the wife of Carmelo Quiles who recently died of Legionnaires disease, pauses in her apartment in an area of the Bronx which is the center of the outbreak on August 6, 2015 in New York City. It is believed that cooling towers in the area contributed to the illness which is believed to be contracted by inhaling mists from contaminated bacteria in the water source. The Bronx, and specifically the area around the Opera Hotel on East 149th Street, is in the middle of the largest outbreak of Legionnaires disease in New York City's history. New York authorities announced that as of Wednesday night the illness has now sickened nearly 100 people since July 10, with at least eight people having died. (Photo by Spencer Platt/Getty Images) NEW YORK, NY - AUGUST 06: People walk past the Opera House Hotel in an area of the Bronx which is the center of the outbreak Legionnaires disease on August 6, 2015 in New York City. It is believed that cooling towers in the area contributed to the illness which is believed to be contracted by inhaling mists from contaminated bacteria in the water source. The Bronx, and specifically the area around the Opera Hotel on East 149th Street, is in the middle of the largest outbreak of Legionnaires disease in New York City's history. New York authorities announced that as of Wednesday night the illness has now sickened nearly 100 people since July 10, with at least eight people having died. (Photo by Spencer Platt/Getty Images) NEW YORK, NY - AUGUST 06: People walk in an area of the Bronx which is the center of the outbreak Legionnaires disease on August 6, 2015 in New York City. It is believed that cooling towers in the area contributed to the illness which is believed to be contracted by inhaling mists from contaminated bacteria in the water source. The Bronx, and specifically the area around the Opera Hotel on East 149th Street, is in the middle of the largest outbreak of Legionnaires disease in New York City's history. New York authorities announced that as of Wednesday night the illness has now sickened nearly 100 people since July 10, with at least eight people having died. (Photo by Spencer Platt/Getty Images) NEW YORK, NY - AUGUST 06: The Opera House Hotel is viewed in an area of the Bronx which is the center of the outbreak Legionnaires disease on August 6, 2015 in New York City. It is believed that cooling towers in the area contributed to the illness which is believed to be contracted by inhaling mists from contaminated bacteria in the water source. The Bronx, and specifically the area around the Opera Hotel on East 149th Street, is in the middle of the largest outbreak of Legionnaires disease in New York City's history. New York authorities announced that as of Wednesday night the illness has now sickened nearly 100 people since July 10, with at least eight people having died. (Photo by Spencer Platt/Getty Images) NEW YORK, NY - AUGUST 06: Carmen Ramirez, whose father Carmelo Quiles recently died of Legionnaires disease, pauses in her mothers apartment with a picture of her father in an area of the Bronx which is the center of the outbreak on August 6, 2015 in New York City. It is believed that cooling towers in the area contributed to the illness which is believed to be contracted by inhaling mists from contaminated bacteria in the water source. The Bronx, and specifically the area around the Opera Hotel on East 149th Street, is in the middle of the largest outbreak of Legionnaires disease in New York City's history. New York authorities announced that as of Wednesday night the illness has now sickened nearly 100 people since July 10, with at least eight people having died. (Photo by Spencer Platt/Getty Images) NEW YORK, NY - AUGUST 06: Carmen Ramirez, whose father Carmelo Quiles recently died of Legionnaires disease, pauses in her mothers apartment in an area of the Bronx which is the center of the outbreak on August 6, 2015 in New York City. It is believed that cooling towers in the area contributed to the illness which is believed to be contracted by inhaling mists from contaminated bacteria in the water source. The Bronx, and specifically the area around the Opera Hotel on East 149th Street, is in the middle of the largest outbreak of Legionnaires disease in New York City's history. New York authorities announced that as of Wednesday night the illness has now sickened nearly 100 people since July 10, with at least eight people having died. (Photo by Spencer Platt/Getty Images) Up Next See Gallery Discover More Like This HIDE CAPTION SHOW CAPTION of SEE ALL BACK TO SLIDE

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