NEW YORK (AP) Sen. Charles Schumer is blaming extreme heat for recent breakdowns and delays New York City's subways and commuter rails.

The Democrat held a news conference Sunday to ask the federal government to step in and find a solution to a problem he says is getting worse.

There have been at least three breakdowns in the past month. And slowdowns have affected Amtrak, the Long Island Rail Road and Metro-North.

The senator says federal investigators should be put in place to protect the systems from heat-related glitches.

On Friday, a freight train derailed on Metro-North's Hudson line. Metro-North spokeswoman Marjorie Anders says heat may have been a contributing factor.

In May, a Metro-North train derailed in Connecticut, injuring 60 people.