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Safety Recommendation Details

Safety Recommendation H-84-050
Details
Synopsis: ON JUNE 28, 1983, A 100-FOOT-LONG SUSPENDED SPAN BETWEEN PIERS 20 AND 21 OF THE EASTBOUND TRAFFIC LANES OF THE INTERSTATE ROUTE 95 HIGHWAY BRIDGE OVER THE MIANUS RIVER IN GREENWICH, CONNECTICUT, COLLAPSED AND FELL 70 FEET INTO THE RIVER BELOW. TWO TRACTOR-SEMITRAILERS AND TWO AUTOMOBILES PLUNGED INTO THE VOID IN THE BRIDGE AND WERE DESTROYED BY IMPACT FROM THE FALL. THREE VEHICLE OCCUPANTS DIED, AND THE OTHER THREE RECEIVED SERIOUS INJURIES. THE NATIONAL TRANSPORTATION SAFETY BOARD DETERMINED THAT THE PROBABLE CAUSE OF THE COLLAPSE OF THE MIANUS RIVER BRIDGE SPAN WAS THE UNDETECTED LATERAL DISPLACEMENT OF THE HANGERS OF THE PIN AND HANGER SUSPENSION ASSEMBLY IN THE SOUTHEAST CORNER OF THE SPAN BY CORROSION-INDUCED FORCES DUE TO DEFICIENCIES IN THE STATE OF CONNECTICUT'S BRIDGE SAFETY INSPECTION AND BRIDGE MAINTENANCE PROGRAM.
Recommendation: THE NTSB RECOMMENDS THAT THE FEDERAL HIGHWAY ADMINISTRATION: REQUIRE EACH STATE TO DEVELOP AN INDIVIDUALIZED INSPECTION PROCEDURE FOR EACH BRIDGE UNDER STATE INSPECTION JURISDICTION THAT HAS CRITICAL ELEMENTS WHOSE FAILURE WILL ALMOST CERTAINLY RESULT IN A CATASTROPHIC FAILURE OF THE BRIDGE.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Highway
Location: Mianus River, Greenwich, CT, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA83AH003
Accident Reports: Collapse of a Suspended Span of Inter- state Route 95 Highway Bridge over the Mianus River
Report #: HAR-84-03
Accident Date: 6/28/1983
Issue Date: 7/19/1984
Date Closed: 6/10/1985
Addressee(s) and Addressee Status: FHWA (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FHWA
Date: 6/10/1985
Response:

From: FHWA
To: NTSB
Date: 11/9/1984
Response: FHWA LTR: MR. LEATHERS, FHWA ASSOCIATE ADMINISTRATOR FOR ENGINEERING AND OPERATIONS, SENT A JULY 16, 1984, MEMORANDUM TO REGIONAL FEDERAL HIGHWAY ADMINISTRATORS IMPLEMENTING A PROCEDURE SIMILAR TO THAT RECOMMENDED (COPY ATTACHED).