LIVE Updates on 4th of July weekend events, fireworks in Chicago area

Ronald Reagan Washington National Airport in Washington, D.C., will temporarily close on July 4 for America 250 celebrations, including flyovers and fireworks.

No flights are scheduled to arrive or depart between noon and 11:59 p.m. ET on July 4. Flights were also temporarily suspended from 10 a.m. to 1 p.m. on July 3 for aerial rehearsals.

Airlines and the Federal Aviation Administration said they worked months in advance to adjust flight schedules to avoid disruptions.

The terminal at Reagan National and parking will still be accessible, officials said.

A parade of Class B tall ships will sail down the East River from 1 p.m. to 4 p.m., starting at the Hell Gate Bridge in Astoria, Queens.

They will pause at South Street Seaport for a review before proceeding to anchoring in Gravesend Bay in Brooklyn, where they will join the larger Parade of Tall Ships on Saturday.

The East River Esplanade and Carl Schurz Park on the Upper East Side and the South Street Seaport should offer excellent views of the ships as they pass by this afternoon.

There is no screening required to watch today's parade of ships.

An ongoing police investigation led to the cancellation of a Fourth of July event in the west suburbs on Saturday.

Glen Ellyn police said Lake Ellyn Park is closed and asked residents to avoid the area.

There will be an increased police presence, but there is no active safety threat, police said.

The Glen Ellyn Park District Freedom 4 Run has been canceled.

Police did not immediately provide further information about the investigation.

The Declaration of Independence was signed in Philadelphia in 1776. ABC News' David Muir was in the room where it all happened - and went into the vault holding some of America's founding documents - including the printer's proof of the Declaration of Independence and the first draft of the U.S. Constitution.