The three people became ill about a week after they stayed at the Plim Plaza Hotel in Ocean Beach, although investigators have not yet confirmed whether they contracted the pneumonia-like disease there, The Baltimore Sun reported Wednesday.
The Harrison Group, which owns the 181-room Plim and nine other hotels, closed the hotel three days before the end of the season to test the water system and address any issues, Betsy FauntLeRoy, Harrison director of marketing, said.
"We have relocated all customers just as a precautionary effort," she said. "We decided to close a couple of days early so everyone would feel more safe and sound."
The disease, also known as legionellosis, is contracted by breathing water mist that contains Legionella bacteria, naturally found in many water systems, health officials said.
"The building has a huge number of guests and high turnover," Dr. Lucy Wilson, a medical epidemiologist for the state Health Department, said. "It's hard in these situations to say something is definitely linked."