NEW YORK (AP) _ Part of the House that Ruth Built came crashing down Monday _ just days before its 75th birthday.

A 500-pound steel joint smashed into the Yankee Stadium stands Monday afternoon, forcing postponement of two games between the New York Yankees and Anaheim Angels and shifting a third game to Shea Stadium.

There were no fans inside the park _ baseball's most storied landmark _ when the steel chunk fell an estimated 40 feet from the underside of the upper deck into the mezzanine section and landed on seats between third base and left field about 2 p.m.

``Yankee Stadium is crumbling. ... Everybody is in a little disarray right now,'' pitcher David Cone said.

More than 20,000 people had been expected at Monday night's game at the stadium, which turns 75 years old Saturday. Mayor Rudy Giuliani said someone almost certainly would have been killed if the collapse had happened during the game.

The 18-inch joint, used to connect beams, crushed one of the blue plastic seats to pieces and gouged a 6-inch hole in the concrete. The joint tore another hole in the ceiling of the upper deck.

While night games Monday and Tuesday were postponed, the Yankees later announced they would play the Angels at 1 p.m. Wednesday at Shea Stadium, home of the rival New York Mets. The Mets are also scheduled to play at Shea that day, at 7:40 p.m. against the Chicago Cubs.

``As a Yankee fan, I'd rather that we were playing, but as a mayor we have to make sure it's safe,'' Giuliani said at the stadium, which is owned by the city and leased to the team.

The earliest the Yankees can play in the stadium is Friday night against the Detroit Tigers. If the ballpark is not ready, the three-game series may be moved to Shea.

The Tigers and Yankees, however, may play instead at Tiger Stadium if the repairs are not finished. Acting commissioner Bud Selig, AL president Gene Budig and the teams discussed a contingency plan Monday night to shift the series to Detroit, and then move the following weekend's series between the clubs from Tiger Stadium to New York.

Babe Ruth christened Yankee Stadium with a homer the day it opened, April 18, 1923, and it has been home to baseball's greatest players ever since. Hall of Famers like Ruth, Lou Gehrig, Joe DiMaggio, Mickey Mantle and Reggie Jackson have helped the Yankees win 23 World Series championships.

``It's a real shame this happened,'' Angels manager Terry Collins said. ``This is a shrine to baseball.''

Bill LeSuer, the Angels' muscle therapist, was walking on the field toward the hallowed Monument Park beyond the left-field fence when the joint fell and landed in section 22, row B, seat 7.

``There was a real loud bang,'' he said. ``I looked up and saw a lot of debris falling down, a lot of concrete.

The stadium was extensively remodeled in 1974 and 1975, forcing the Yankees to play at Shea until it reopened in 1976. Yankees owner George Steinbrenner has been trying to get a new ballpark, complaining the current stadium doesn't have enough parking and amenities.

He was at his Tampa, Fla., home at the time of the accident.

Stadium superintendent Bob Wilkinson said the ballpark is inspected once a year. He said crews would work through the night Monday to check ``every nook and cranny.''

``There is a lot of foundation work and steel still here from 1923,'' he said. ``But this stadium is in good shape. This is an isolated incident.''

The Yankees plan to play a practice game Tuesday afternoon at the stadium against their Double-A Norwich team, although fans won't be allowed in. The Angels also will work out at the park.

After the team announced that the game was postponed, people milled outside the stadium and police told fans at subway stops to turn right around and go home.

``We're going to send a telegram to the Mariners tonight saying `You don't want to play here. It's not safe,'' said Jim Burton, a high school teacher who had brought a whole class from Seattle to watch the game.

The Yankees have talked about building a new stadium near Madison Square Garden in Manhattan, or one near Giants Stadium in East Rutherford, N.J. The team's lease at Yankee Stadium runs through the 2002 season.

Yankee Stadium is fourth-oldest ballpark in the majors, behind Tiger Stadium (1912), Boston's Fenway Park (1912) and Chicago's Wrigley Field (1914).

This was not the first time a structural problem has postponed ballgames.

At the Kingdome in Seattle in 1994, four acoustic roof tiles fell on empty seats before a scheduled game. The Mariners had to spend the final 22 days of the strike-shortened season on the road.

In 1991, Olympic Stadium in Montreal was closed after a 55-ton concrete beam crashed onto a walkway, forcing the Expos to play their last 13 home games on the road.

In 1995 at the SkyDome in Toronto, two wood tiles from an upper deck fell during a game, injuring at least seven fans. At the 1989 World Series, Candlestick Park was rocked by a major earthquake that caused minor damage to the ballpark. Game 3 of the Series was postponed for 10 days.