WATERLOO — The Annbriar Golf Course is still open for business after a sinkhole on Friday swallowed a player as he stood on a fairway.

Mark Mihal, a mortgage broker from Creve Coeur, Mo., and the operator of the fantasy golf website golfmanna.com, was standing on the 14th fairway at Annbriar waiting for his next shot when the ground gave way below his feet and swallowed him up.

The next thing the golfer knew was that he was at the bottom of a 15-foot-deep, 10-foot-wide pit with a separated shoulder.

"I felt the ground start to collapse and it happened so fast that I couldn't do anything," Mark Mihal was quoted as saying on his website. "I reached for the ground as I was going down and it gave way, too. It seemed like I was falling for a long time. The real scary part was I didn't know when I would hit bottom and what I would land on."

His friends, watching from a short distance away, thought Mihal had fallen down a hill, said Ed Magaletta, who was golfing with Mihal. When Magaletta and friends realized Mihal had fallen into a sinkhole, they sprang to action, calling the clubhouse for help and moving in to assess the danger. Annbriar General Manager Russ Nobbe called 911, grabbed a ladder and rope and rushed from the clubhouse to the scene.

Being held by his ankles, Magaletta inched toward the sinkhole that he described as looking like a rip in carpet. Magaletta then used a flashlight he had in his pocket to assess the egg-shaped hole and determined there was no danger it would collapse.

Mihal was in too much pain to climb the ladder lowered into the hole, so Magaletta climbed down to help. Magaletta fashioned a sling from his clothing to stabilize Mihal's shoulder. With help of people above pulling on the rope around him and Magaletta pushing from below, Mihal ascended the ladder, was loaded into a waiting ambulance and taken to a nearby hospital for examination.

Magaletta said he never thought of his own safety or waiting for first responders to rescue his friend.

"It had to be done to get him out, Magaletta said, "They had the rope and the ladder. It was kind of silly to stand around and wait."

A pre-med major at St. Louis University and from a family of medical professionals, Magaletta said he was the natural choice among those present to descend into the hole to help the injured Mihal.

Nobbe called the incident an "act of God," and said there was no way to anticipate it.

"We don't think there was a way we could have foreseen this or prevented it," Nobbe said.

Professional geologist Philip Moss said there is almost no chance a similar incident could occur on the course.

"There will be others in this area, but the odds of this happening with a person standing there are infinitesimal."

Nobbe said the course is open because it is safe, but Moss said there is no authority in the area to officially declare the course safe for play. The course has not been inspected for the presence of additional sinkholes, a process Moss said would not help because that type of sinkhole does not leave any visual evidence. Technology does exist to perform the inspection, but Moss said it is very expensive and he is not aware of anyone using it in similar circumstances.

There were a few people playing the course Tuesday, avoiding the closed 14th hole.

Sinkholes in Monroe County are nothing unusual, according to C. Pius Weibel, senior geologist with the Illinois Geological Survey.

Weibel called Monroe County the "sinkhole capitol of Illinois." There are more than 10,000 sinkholes accounted for in southwestern Illinois.

According to the U.S. Geological Survey's online maps, there are more than 25 sinkholes already mapped within 500 feet of the Annbriar Golf Course, not including the one that appeared Friday.

"Sinkholes are extremely abundant in Monroe County, especially in the western part," Weibel said. "There are three things you need to form sinkholes: Heavy rainfall or precipitation, soil and dissolvable bedrock. In western Monroe County, there is a lot of limestone bedrock to the west. Conditions are prime for sinkholes."

Weibel said sinkholes most often occur when periods of heavy rain follow dry periods.

"That's why you see sinkholes like the one that recently happened in Florida," Weibel said. "It's when the dry season ends and a rainier period begins."

The metro-east had been in a drought that dated back to last summer before recent rains pulled it out of the dry weather pattern.

According to National Weather service hydrologist Mark Fuchs, Monroe County had 5 1/2 to 6 inches of rain during the last month and a half.

"That's quite a bit of rain for that period," Fuchs said. "The normal in the area for that period of time is about 3.4 inches. So we've had almost twice as much rain in that time period as we'd normally expect."

Fuchs said Monroe County was officially in a D-3 classification on the weather service's drought scale, which represents "extreme drought," until last week -- when recent rain and snow finally erased the water deficit the area had faced dating back to May.

Describing the creation of sinkholes as "a very slow process with a sudden termination," Moss said it was surprising that the sinkhole hadn't opened up under the weight of recent rain. Sinkholes open up several times a year in farm fields in the area, but they usually open during a storm, which is why people aren't typically at risk of getting trapped, Moss said.

After the hole is fully excavated, it will be filled with rocks and covered with sod. Weather permitting, Nobbe expects the process to take a few days.

On Feb. 28 in a Tampa, Fla., suburb, a much larger sinkhole estimated at 30 feet in diameter and 50 feet deep swallowed 37-year-old Jeff Bush, who was in a bedroom of a one story home.

His brother Jeremy Bush tried to rescue him by slipping into the sinkhole and digging with a shovel, but police stopped him because of the danger that he could also be trapped. The victim's body was never retrieved and the home, which had partially fallen into the hole, has since been demolished and the hole filled in. This part of Hillsborough County is known as "Sinkhole Alley."

Information from: St. Louis Post-Dispatch, http://www.stltoday.com