The fire was reported shortly before 6 a.m. in the 300 block of S. Fulton Ave., in the Carrollton Ridge neighborhood in Southwest Baltimore. Fire Capt. Roman Clark said the first and second floors were engulfed in flames when firefighters arrived.
Johns Hopkins Bayview Medical Center, the other at Maryland Shock Trauma Center. Their ages and conditions were not immediately known.
The child who may have been thrown from the second-floor window is an infant whose exact age was not known, Fire Chief Kevin Cartwright said.
Clark said investigators are checking reports that the youngster was caught by a bystander. The fire spokesman said an injured child was taken to Johns Hopkins Hospital.
Cartwright said the one-alarm fire was under control at 7:20 a.m. The cause remains under investigation, and Clark said police arson detectives are assisting.