In the weeks prior to the fatal collapse of a Manhattan lower parking structure in 2023, the employees of the garage operator Little Man turned damaged bricks and mortar from a loading dock without having a permit for the work, according to a recently published report prepared by Lera Consulting Engineers Rllp for the New York City Department. The removal of the material triggered the collapse, but it was not the only problem that faced the structure.
A person died on April 18, 2023, collapsed and several others were injured.
“The reckless direction of these workers to eliminate the bricks from the dock, together with the lack of informing the problem in DOB, obtain the necessary construction permits and install the critical structural crushing, caused this building to be reduced,” said New York Building Commissioner, Jimmy Oddo, in a statement.
The three -story garage, located at 57 Ann St., consisted of concrete slabs reinforced with soldier thread fabrics and supported in concrete steel beams and beams, which were supported by internal concrete steel columns and walls of walls and non -exposed brick cargo cuffs. It was originally built in 1925 and was modified several times over the following decades. What may have been its most structurally significant alterations in the 1950’s, when the crews decreased the skylights and the attached parking capacity to the roof.
Long -term progressive deterioration and stress of original design and construction deficiencies caused vertical cracks in a specific dock researcher identified as the point of origin of collapse, according to the report.
According to the report, the wharf in question was not designed or built in compliance with the 1916 construction code, without sufficient structural safety margin between its design load and its final capacity. Researchers found that simple beams are replaced by the double beams shown in the 1925 drawings, but the bearing plate in each beam was not sized to match the combined area of support plates required by the drawings, causing higher tensions than those waiting for them. The dock was built against a pre -existing shared festival wall, but it was not substantially integrated into the wall by denoting enough bricks through the interface between the dock and the wall. This caused that the connection could not distribute concentrated loads from the beams on the floor to the wall.
The dock suffered a progressive deterioration that researchers attributed to natural aging, long -term exposure to humidity and high stresses related to design and construction deficiencies.
Researchers wrote maintenance and repairs did not adequately address the cracks on the dock. They found that EDG, an engineering company that inspected the structure for the owner to fulfill the requirements of the city’s periodic inspection for parking structures (PIPS), seemed incorrectly supposed that the dock was to fit non -structural bricks in a structural steel column, instead of a solid brick structural wharf. The firm did not require the plot and the probe to verify the case and no one identified the deterioration as a non -safe condition or reported it to DOB.
Neither EDG nor Little Man Parking responded immediately to a journalist’s consultations.
Image courtesy of New York Building DepartmentIn March 2023, garage employees began to remove some bricks and mortar from the damaged dock, although the work had not been allowed. An employee of the garage started removing more material on the morning of the day the garage collapsed. That afternoon, an engineer EDG told the car park’s employees that they replaced the bricks, but did not identify a non -safe condition, notified DOB, recommended shaking or communicating urgently in the direction of replacing bricks, according to the report. The bricks were not replaced.
Around 16:04 of the collapse day, a garage employee drove a vehicle ahead of the damaged wharf, which the engineers wrote, increased the tensions of the support between the beam and the remaining bricks and the mortar. Increased tensions probably crushed the remaining bricks and mortar, allowing a third -floor beam to fall from several inches. This created a gap above the beam, which left the highest story of the dock without enough support. The connection between the upper story of the dock and the wall wall failed a few seconds of the passing car, allowing the upper story of the dock to slip down, which allowed the roof beam to collapse on the third floor. The third floor collapsed on the second floor and the second on the first.
“ This tragedy highlights the importance of property owners and managers being aware and fulfilling all the regulations of the city, and for design professionals hired to evaluate and design repairs and modifications to existing buildings to exercise care to identify and address the non -safe conditions in a timely and appropriate manager, ” said Benjamin Cornelius, a member of LERA, in a statement.
The engineers also pointed to the deterioration of rainwater that were put on the roof and land, as well as other non -allowed works, including repairs of concrete slabs and labels, alterations in the steel frame and the installation of car stacking as possible factors.
Execution and violations
DOB issued seven civilian violations to the owners after collapse. Officials also issued an order from the commissioner that required inspections to the parking structure in New York City associated with EDG or Little Man Packing to undergo a third -party review of an independent engineering company.
The officials also made a sweep of the parking structures associated with companies and said that as a result, additional execution actions are issued.
DOB is also in the process of contracting for a newly created execution unit focused on inspecting buildings that have fallen in poor condition, which officials say that they will be addressed to negligent owners and bad actors in the construction industry. The new unit is expected to start operating later this year.
“We have strict regulations in our codes aimed at preventing collapses like this, but these regulations do not keep anyone sure if they are not followed,” said Oddo. “That is why we are customizing a new DOB dedicated to a new proactive application strategy, with the aim of finding and stopping these non -safe construction operations before a possible collapse can occur.”
The Lera report also offered several recommendations for potential reviews to city construction codes to help reduce the risk of a similar collapse in the future.
These recommendations include requires qualified parking structure inspectors that direct a site evaluation in the PIPs program to review all available DOB drawings and property owners and require the inspector to visit the site at least once before planning an evaluation. Engineers recommend that the registered design professional contracted to design structural repairs also need to obtain all available drawings, visit the site during evaluations and prepare signed and sealed drawings that identify any piece that will be needed.
