Lights shine through the fog during play between the Chicago Bears and the Philadelphia Eagles at their semi final NFC playoff game in Chicago, Saturday, Dec. 31, 1988. A heavy fog enveloped Soldiers Field creating decreased visibility. (AP Photo)

The Chicago Bears defense huddles and is barely visible as a thick fog rules in during the 1988 NFL NFC Divisional playoff football game against the Philadelphia Eagles on Dec. 31, 1988 in Chicago. The Bears won the game 20-12. (Paul Spinelli via AP)

A thick fog rolls in as Chicago Bears defensive linebacker Al Harris (60) leaps high trying to block a field goal attempt during the 1988 NFL NFC Divisional playoff football game against the Philadelphia Eagles on Dec. 31, 1988 in Chicago. The Bears won the game 20-12. (Paul Spinelli via AP)

Philadelphia Eagles quarterback Randall Cunningham (12) calls a play in the huddle during the NFC Divisional Playoff, a 20 - 12 loss to the Chicago Bears in the fog on Dec. 31, 1988, at Soldier Field in Chicago. (Al Messerschmidt via AP)

A thick fog rolls in as the Chicago Bears defense gets set as the Philadelphia Eagles offense gets ready to snap the ball at the line of scrimmage during the 1988 NFL NFC Divisional playoff football game against the Philadelphia Eagles on Dec. 31, 1988 in Chicago. The Bears won the game 20-12. (Paul Spinelli via AP)

The crowd pulls for their team during the NFC Divisional Playoff, a 20-12 Chicago Bears victory over the Philadelphia Eagles on December 31, 1988, at Soldier Field in Chicago, Illinois. (National Football League)

Chicago Bears defensive tackle Dan Hampton (99) and linebacker Mike Singletary (50) watch as the fog rolls in during the NFC Divisional Playoff, a 20 - 12 victory over the Philadelphia Eagles on Dec. 31, 1988, at Soldier Field in Chicago. (Al Messerschmidt via AP)

The Chicago Bears offense lines up in the fog during the NFC Divisional Playoff, a 20-12 victory over the Philadelphia Eagles on December 31, 1988, at Soldier Field in Chicago, Illinois. (National Football League)

Chicago Bears free safety Maurice Douglass (37) runs out of the fog and is congratulated by teammates after intercepting Philadelphia Eagles Randall Cunningham late in the fourth quarter, Saturday, Dec. 31, 1988 in Chicago. The interception stopped an Eagles drive and allowed the Bears to run out the clock for a 20-12 win and a trip to the NFC Championship game. (AP Photo/Mark Elias)

Chicago Bears running back Neal Anderson (35) is tackled by Philadelphia Eagles linebacker Todd Bell, left, and cornerback Eric Allen, right, during the NFC playoff game, Saturday, Jan. 2, 1988 in Chicago. Anderson scored one touchdown and rushed for 54 yards to help the Bears defeat the Eagles 20-12. (AP Photo)

Philadelphia Eagles quarterback Randall Cunningham (12) comes out of the fog to throw a pass during action in their semi-final NFC playoff game against the Bears in Chicago, Saturday, Dec. 31, 1988. (AP Photo/Rob Kozloff)

Fog settles over the stadium during the NFC Divisional playoff, a 20-12 Philadelphia Eagles loss to the Chicago Bears on December 31, 1988, at Soldier Field in Chicago, Illinois. (National Football League)

Chicago Bears head coach Mike Ditka watches from the sideline as Dennis McKinnon (85) walks from the field in Chicago, Dec. 31, 1988. The Bears beat the Philadelphia Eagles 20-12 while playing in a dense fog. (AP Photo/Rob Kozloff)

The Philadelphia Eagles, including linebacker Scott Curtis (91) cornerback Izel Jenkis (46), huddle up during the NFC Divisional Playoff, a 20-12 loss to the Chicago Bears on December 31, 1988, at Soldier Field in Chicago, Illinois. (National Football League)

Philadelphia Eagles defensive end Reggie White (92) gets a postgame hug from Chicago Bears linebacker Mike Singletary (50) and Bears defensive back Dave Duerson (22) after the NFL Divisional playoff football game against the Chicago Bears on Dec. 31, 1988 in Chicago. The game was known as "The Fog Bowl" due to the heavy fog that rolled in off the lake during the game. The Bears won the game 20-12. (AP Photo/Paul Spinelli)

Philadelphia Eagles quarterback Randall Cunningham (12) drops back to pass against the Chicago Bears defense during the 1988 NFC Divisional Playoff NFL game in Chicago on December 31, 1988. The Bears defeated the Eagles 20-12 in the "Fog Bowl." (AP Photo/Kevin Terrell)

Chicago Bears linebacker Mike Singletary (50) talks with Philadelphia Eagles quarterback Randall Cunningham (12) after the NFC Divisional Playoff, a 20 - 12 Bears victory in the fog on Dec. 31, 1988, at Soldier Field in Chicago. (Al Messerschmidt via AP)

Chicago Bears wide receiver Dennis Gentry (29) tries to get past a defender during the NFC Divisional playoff, a 20-12 victory over the Philadelphia Eagles loss on December 31, 1988, at Soldier Field in Chicago, Illinois. (National Football League)

Philadelphia Eagles defensive end Clyde Simmons on the sidelines during the NFC Divisional Playoff, a 20-12 loss to the Chicago Bears on December 31, 1988, at Soldier Field in Chicago, Illinois. (National Football League)

A thick layer of fog covers the field during the NFC Divisional Playoff, a 20-12 Chicago Bears victory over the Philadelphia Eagles on December 31, 1988, at Soldier Field in Chicago, Illinois. (National Football League)