Every few years, one of the eight surviving Union Pacific Big Boy locomotives goes on a national tour, drawing hundreds and thousands of rail fans, history buffs and spectators at the whistle stops on its schedule. Unfortunately, over 100 of the thousands who gathered in Reading, Pennsylvania, to see Big Boy #4014 on July 2nd were treated at the Reading & Blue Mountain Railroad Outer Station for heat-related conditions after temperatures soared to 103℉. Of the affected, 35 were hospitalized, including one person who experienced cardiac arrest.
The Muhlenberg Township Police Department, which responded to the event along with the local Ambulance Association and Fire Company, described what occurred as a “mass casualty incident” in a social media post. While the phrase may evoke deadlier events like mass shootings or multi-car highway crashes, the term simply refers to any event that results in a number of patients that exceeds available medical resources. By declaring the situation at Reading Station a mass casualty event, the police were able to coordinate a larger-scale emergency response.
Related: The Underrated East Coast City Just Voted the ‘Best Place to Celebrate the Fourth of July’
Big Boy #4014 spent just shy of two weeks in Scranton, Pennsylvania at the Steamtown National Historic Site, in part for locomotive maintenance. 55,000 people reserved tickets just for that leg of the trip, including 26,000 tickets for the first day of the layover. The Reading event was the Big Boy’s next stop on the tour. Eager attendees lined up early to get a good vantage point, some waiting for hours ahead of the train’s arrival.
Unfortunately, the train arrived just days after a punishing heat dome settled over the northeastern United States. The same record-breaking weather system spiked temperatures to over 100℉ in Washington D.C. on Friday, shaking up the Great American State Fair when organizers postponed Freedom 250 for four hours due to dangerous heat.
Temperatures will still be scorching when the Big Boy pulls into Philadelphia on July 4 for the City of Brotherly Love’s America250 Block Party. It will be publicly viewable from 8:00 a.m. – 2:00 p.m. EDT on the Fourth of July and on July 5 from 9:00 a.m. – 3:00 p.m. EDT.
The Union Pacific website advises in an FAQ that “Extreme heat is possible, so please plan ahead. Drink plenty of water, wear lightweight clothing, and apply sunscreen regularly. Take breaks in shaded areas, and avoid prolonged exposure to direct sunlight. Be aware of symptoms like dizziness, headache, or nausea—if you feel unwell, seek assistance immediately.”
Philadelphia has already cancelled some of its planned events for the 250th anniversary of the adoption of the Declaration of Independence, including a Salute to Independence Semiquincentennial Parade that was scheduled for Friday, July 3rd. Washington D.C. has also cancelled its DC’s National Independence Day Parade that was to occur the morning of July 4, when temperatures are forecasted to hit 93 degrees by 10 a.m.
The Big Boy isn’t the only train affected, either. The same day as the mass casualty event in Reading, NJ Transit was disrupted by the high temperatures, stranding some passengers in Harrison, while others sweated in Penn Station, which has no air conditioning. Amtrak has cancelled dozens of trains and is operating others at reduced speeds to account for the way heat affects the tracks.
Related: 10 Years Before Route 66, This Highway Crossed the U.S. and You Can Still Drive It Today
After its stints in Pennsylvania, including stops in Lebanon, Altoona, Leetsdale, and Historic Horseshoe Curve, Big Boy #4014 will steam south to Missouri before returning west through Kansas, Colorado and Wyoming, where it returns home to Cheyenne. The Western leg of the tour began in Cheyenne on March 29, passing through Utah, Nevada, and California on the way to Sacramento, California, where Mile 0 of the transcontinental railroad was built in 1863. Big Boy #4014 returned across the Rocky Mountains to being the Eastern leg of the tour in late May in Kimball, Nebraska. Stops included stations in Iowa, Illinois, Indiana, Ohio and New York on its way to Philadelphia for the Fourth of July.
Only 25 Big Boys were ever built, living up to the name with a 133-foot-long frame that weighs 1.2 million pounds, or roughly the same as two Boeing 747 aircraft. These engines were, and are, the world’s largest operating steam locomotives. The Big Boy fleet ran between Ogden, Utah, and Cheyenne, Wyoming for 20 years, before Big Boy #4014 was retired to Cheyenne after a brief stint at the RailGiants Train Museum in Pomona, California. Other cities with a Big Boy in permanent residence include Denver, Colorado; St. Louis, Missouri; Omaha, Nebraska; Scranton, Pennsylvania; Dallas, Texas; Green Bay, Wisconsin; and Cheyenne, Wyoming.
This story was originally published by Parade on Jul 4, 2026, where it first appeared in the Travel section. Add Parade as a Preferred Source by clicking here.