Excerpts from the ChicagoTribune.com:

Jessica Johnson woke to the sounds of screaming but thought it was just a Cubs fan straggling home late from Wrigley Field six blocks away. She went to the window anyway. “He was yelling, ‘Get out. Get out. Get out,’ ” said Johnson, who dressed, grabbed her keys and ran outside barefoot.

“Once in the front, I saw flames shooting out of the side of the building,” she said. The man she heard yelling was on the sidewalk, bleeding.  Neighbors were running outside and calling 911.

Two people inside the three-story apartment building in the 3400 block of North Janssen Avenue in Lakeview jumped to safety and two others were rescued by firefighters, according to Deputy District Fire Chief John Shehan.  All four were taken to hospitals in serious-to-critical condition.

The fire started about 1:50 a.m. in a rear apartment on the third floor of the six-unit building, Shehan said at the scene. The fire department was initially called to an address in the 3400 block of North Southport Avenue, a block east.  Firefighters lost a minute or two while searching for the building that was on fire until they got a second call with the right address.

“A minute or two (can make) a big difference,” Shehan said. “There was a lot of fire venting from the apartment.”

A 22-year-old man and a woman, whose age was not available, were taken to Advocate Illinois Masonic Medical Center, police said.  A 35-year-old man and a 23-year-old woman were taken to Northwestern Memorial Hospital, police said.

The cause of the fire was under investigation. The police Bomb and Arson Unit was inspecting the site as part of standard procedure.