2007 New York City steam explosion

Consolidated Edison

Industry	Utilities
Founded	1884
Headquarters	New York City , United States
Products	Steam service, electricity, gas

On July 18, 2007, a powerful steam eruption erupted beneath a bustling intersection in Manhattan, New York City, propelling a towering column of mud and debris nearly 40 stories into the air over Midtown Manhattan. This incident resulted from the rupture of an 83-year-old underground steam pipe situated close to Grand Central Terminal, which burst during the evening rush hour. The event caused injuries to 45 individuals and led to the death of a woman who suffered a fatal heart attack while escaping the scene.

Authorities, including Mayor Michael Bloomberg, promptly ruled out terrorism as a cause shortly after the explosion.

Background

Since 1987, New York City has experienced over a dozen similar steam pipe failures linked to Con Edison. A significant blast near Gramercy Park in 1989 claimed the lives of two Con Edison employees and one bystander, resulting in extensive property damage worth millions. Following that accident, the company admitted to hiding asbestos contamination and was fined $2 million. Another notable explosion occurred at Washington Square Park in 2000, creating a 15-foot-wide crater and dispersing asbestos fibers.

The origin of steam service in Lower Manhattan dates back to 1882 with the New York Steam Company. Currently, Con Edison manages the world’s largest commercial steam network, encompassing more than 100 miles of steam piping. This infrastructure supplies nearly 2,000 clients across upwards of 100,000 residential and commercial buildings located south of 96th Street. In 2007, the system’s pipes averaged 54 years in age, with some approaching a century since installation.

Event

The explosion took place shortly before 6:00 p.m., coinciding with peak evening traffic, and was triggered by the failure of a 24-inch steam pipe installed in 1924 by Consolidated Edison. Positioned at the intersection of 41st Street and Lexington Avenue near Grand Central Terminal, the blast propelled a steam plume taller than the Chrysler Building’s 1,047-foot height that lingered for at least two hours. The blast also created a crater approximately 35 feet across and 15 feet deep.

Nearby office structures trembled from the force of escaping steam, leading to rapid evacuations. Among those affected was a 51-year-old woman from New Jersey who died from a heart attack while fleeing. Of the 45 injured, two were critically harmed; notably, a 23-year-old tow truck driver from Brooklyn suffered severe burns over more than 80 percent of his body due to exposure to steam heated to around 400°F and was placed in an induced coma. His passenger, aged 30, was also injured while returning home after her vehicle broke down. Eyewitnesses described how the tow truck was propelled approximately 12 feet into the air by the escaping steam—rising higher than a nearby city bus.

Cause

The official investigation report was published on December 18, 2007. Engineers were unable to evaluate damage within the crater until after the tow truck’s removal on July 22, with asbestos contamination further complicating on-site examination.

Con Edison’s formal report, issued on December 27, 2007, identified faulty contractor repairs as the root cause of the pipe rupture. Excessive sealant applied during an earlier joint repair obstructed two steam trap valves responsible for draining condensate water. On the day of the incident, heavy rainfall cooled the pipe substantially, generating surplus condensate that could not be expelled due to valve blockage. As a precautionary measure, over 1,600 similar valves throughout the system were replaced; however, no additional blockages were discovered.

States of water

One possible explanation proposed was steam hammer, a process occurring when cold water comes into contact with a hot steam pipe, causing the steam to condense into liquid water and create a destructive multi-phase flow. This event might have been triggered by runoff from intense rainfall or a nearby water main break close to the crater. Although a broken water main was discovered near the steam pipe, it remains uncertain whether it was a cause or an effect of the incident. Initial utility reports indicated no pressure increase before the explosion; however, these were later updated to acknowledge a sudden internal over-pressurization caused by water hammer reaching at least five times normal pressure levels.

The interaction with cold water may have also imposed stress on the cast iron pipe, contributing to its failure. Despite concerns about corrosion due to the pipe’s age and difficulties in inspecting it, a representative from New York State’s safety authority stated during a September 2007 Public Service Commission meeting that there was no evidence of corrosion-related deterioration or weakening.

Leaks

In the weeks leading up to the explosion, ongoing steam leaks and repair efforts had been recorded in the vicinity, with utility personnel having inspected the site just six hours prior to the event. Early investigations revealed that a recently repaired seam remained intact, while the pipe ruptured suddenly approximately 10 feet away.

Engineer Robert Caligiuri, hired by attorneys representing one of the victims, attributed the failure to an “old crack-like defect” in a welded seam, claiming it was significant enough that Con Edison should have identified and replaced that section of pipe. The utility contested this assertion, stating that independent engineering evaluations found no previous deterioration and that the weld itself did not cause the rupture but was forcibly opened during the failure.

Asbestos

The pipes, dating back over a century, were frequently insulated with asbestos, resulting in the area being designated as an “asbestos containment zone.” Although asbestos was detected in solid debris at the site, air samples did not reveal any friable asbestos particles. Nevertheless, personnel entering this zone were required to wear respirators and protective gear during cleanup operations, due to lingering doubts stemming from earlier false assurances about air safety following major incidents.

More than 100 evacuees and rescue workers underwent decontamination processes, which included testing their clothing for contamination. Initially, affected residents were instructed either to discard or separately launder contaminated garments; later guidance directed them to bag their clothing for disposal by the utility company with reimbursement provided.

Emergency response

The New York City Fire Department rapidly escalated their reaction to a five-alarm level, deploying over 200 firefighters from 40 units. Among those responding were three injured firefighters and one injured police officer. In total, more than 500 police officers and firefighters participated in managing the emergency.

Con Edison treated this as an “all hands event,” doubling worker shifts to deploy all available utility employees. Initially, the steam leak was left active deliberately to prevent additional ruptures. After securing control of the site, the fire department raised their response further by issuing a sixth alarm for reinforcements.

The New York City Police Department established a “frozen zone” covering several blocks from 40th to 43rd Streets between Vanderbilt and Third Avenues, restricting pedestrian movement. This measure prevented residents from returning home that evening and kept thousands from accessing their workplaces the following day, although individuals already present in the area were not evacuated. Additionally, multiple streets were closed off to vehicle traffic.

Short-term interruptions

Service disruptions affected 15 to 20 buildings, with telephone and Internet connections also experiencing outages. Although an underground electrical transformer and feeder cables were damaged, widespread power failures did not occur; however, customers were encouraged to minimize their electricity usage. Cellular networks became overwhelmed immediately following the incident.

Public transit, including bus and subway operations, was also disrupted. In Manhattan, the 42nd Street Shuttle along with the IRT Lexington Avenue Line and trains were temporarily halted, while the train was diverted via the IRT Broadway – Seventh Avenue Line. The subway infrastructure itself remained unharmed. Services resumed overnight before the morning peak, initially skipping stops at Grand Central – 42nd Street. Shortly after the explosion, Grand Central Terminal underwent a partial evacuation, with entrances facing the blast site closed; nonetheless, Metro-North Railroad commuter trains experienced minimal disruption. By the next evening, access points at Vanderbilt Avenue and Third Avenue were reopened.

Authorities projected that cleanup and repairs would require at least one week, though no exact completion date had been provided as of July 21. The prolonged environmental remediation presented considerable transportation and economic challenges due to the location within one of New York City's most active and high-value commercial areas. Approximately 700,000 commuters pass close to Grand Central every day.

Businesses located within the restricted area faced substantial losses, with initial estimates reaching up to US$30 million in damages; these figures could rise into the hundreds of millions if cleanup extended beyond a week. By July 21, the restricted zone had shrunk to four blocks between 40th and 42nd Streets from Park to Third Avenue. Among those unable to enter their offices was a law firm representing Con Edison as a lobbying client. Con Edison committed to reimbursing direct damages and cleanup expenses but explicitly excluded compensation for business interruption costs such as lost revenue or decreased productivity.

Litigation

The first lawsuit against the utility was filed by a Brooklyn resident who claimed that the explosion's trauma triggered memories of her sister’s death during the 9/11 at the World Trade Center. On July 30, the family of the tow truck driver involved also initiated legal action against Con Edison.

Another plaintiff suffered serious injuries—specifically ankle and knee damage requiring multiple surgeries—while evacuating from the blast vicinity. Following her passing due to cancer, her son announced a settlement agreement with both the city and Con Edison. Her experience was chronicled by her son, who is a producer on the Ron and Fez show broadcast on Sirius XM Radio.

Political consequences

New York City Council member Daniel Garodnick scheduled hearings at City Hall regarding the explosion for August 7. In light of earlier scrutiny following the 2006 Queens blackout—during which Con Edison CEO Kevin Burke faced intense questioning—city legislators, including Speaker Christine Quinn, expressed diminished trust in Con Edison and hinted at reconsidering its monopoly privileges.

Kevin Burke did not attend the hearing personally; instead, senior vice president William Longhi represented the company. This absence provoked frustration among council members. Longhi offered only limited details due to the ongoing investigation, resulting in tense discussions. Leroy Comrie, chair of the Consumer Affairs Committee, advocated for either assuming control of or dismantling Con Edison.

Michael N. Gianaris, a New York State Assemblyman from a Queens district affected by the incident, urged that Con Edison be required to compete for managing the city's power infrastructure and subjected to yearly audits by the New York Public Service Commission.

On December 27, 2007, Councilman Eric Gioia condemned Con Edison for court documents implying that city infrastructure might have played a role in the explosion, accusing the utility of shifting responsibility despite clear signs of inadequate upkeep.

In Boston, Massachusetts, Mayor Thomas Menino leveraged New York’s incident to advance stalled state legislation governing commercial steam distribution systems, following a serious steam pipe injury there two months earlier.

Philadelphia manages an extensive steam pipe network through Veolia Energy Philadelphia and has not experienced recent incidents comparable to New York’s event. Although a steam explosion in 1989 caused property damage, officials commended current utility maintenance standards after New York’s occurrence.

See also

• New York City steam system
• District heating
• Water hammer

External links

• Raw surveillance footage of the street moments before the steam pipe explosion
• Video of erupting steam looking west from 41st Street and Third Avenue