LITTLETON, Colo. -- Two men who were fighting, broke through an apartment stairwell railing and plunged 20 feet on concrete stairs early Monday, Littleton police said.

The men, described as friends who grew up together, were in critical condition at Swedish Hospital, police Lt. Sean Dugan told TheDenverChannel.com.

"They're both hurt badly and they're both in intensive care," Dugan said.

Police received the first call at 2:22 a.m. about men arguing on the third-floor outdoor stairwell at the Terra Vista apartments, 5481 S. Federal Circle.

Then another 911 caller reported "two people have gone over the railing," Dugan said.

The railing was secured with both screws and nails, suggesting it might have been reinforced at some point, he said.

"They broke completely through it," Dugan said.

Arriving officers found the two men, both in their early 20’s, who were semi-conscious and laying at the bottom of a concrete stairwell, he said.

One of the men had an obvious, severe head injury, Dugan said.

Police are getting conflicting accounts about what triggered the fight between two buddies.

"There was some type of altercation," Dugan said. "We don't believe that it was just roughhousing or partying," he added.

"We believe alcohol was a factor," he added.

One of the men lived in an apartment where the fall occurred.