HOUSTON --A fast-moving fire provided an early wake-up call Friday morning for dozens of people. Amid the smoke and flames, one man was seriously injured while trying to escape from the fire. The man remains in the hospital this morning after he was seriously injured trying to escape from the second story of his southwest side apartment. Fire crews quickly put out the fire. Witnesses say they saw a man who had to jump from a second floor window. The fire victim suffered serious burns after apparently becoming trapped. The flames were first spotted just after 4am at the Three Fountain apartment complex on Burgoyne near Nantucket in southwest Houston. Arson investigators have been on the scene all morning, looking into what they say is a suspicious fire. "It just happened so fast," said resident Edward Glaser. The fire which blackened four units of this building didn't reach his apartment, but it certainly woke up Glaser. "I was sleeping and I heard a bang," Glaser said. Other residents told us they heard the same. "We heard a loud boom. We live next door, we looked out the bedroom window," said eyewitness Jennifer Jacks. What neighbor Jennifer Jacks saw was unlike anything she'd ever seen before -- a man, seriously injured, and struggling to get out the window of his second story apartment. "There was a gentleman hanging out this top corner window a second story window, begging to get him out, 'Please help me, help me.' The aluminum frame was holding him in," said eyewitness Jennifer Jacks. "We kept telling him, 'Come on, baby, push out, push out.' He finally broke through and he rolled on the side of this building and down on the grass. It was just awful." The man suffered serious burns and ended up at the hospital, while firefighters spent the better part of the morning on the scene. "They must suspect arson because they had the arson dogs here," said Glaser. And that's exactly what authorities suspect. Firefighters called arson investigators to the scene right away because the fire involved a stairwell, which is suspicious. "Oh it's scary. I had a fire at my complex about 20 years ago. So you never know when something like that is going to happen," said neighbor Liz Bennett. The injured man's condition is unknown at this time. No one else was hurt in the blaze. The cause of the fire is still under investigation.