41 years ago a fatal ammonia truck disaster claimed the lives of several Houstonians

This photo shows the ammonia truck's chassis and vehicle parts being hauled away after the fatal accident and chemical spill of May, 11, 1976. This photo shows the ammonia truck's chassis and vehicle parts being hauled away after the fatal accident and chemical spill of May, 11, 1976. Photo: Chronicle File Photo: Chronicle File Image 1 of / 20 Caption Close 41 years ago a fatal ammonia truck disaster claimed the lives of several Houstonians 1 / 20 Back to Gallery

May 11 marks the 41st anniversary of one of the scariest moments in Houston history, when a semitrailer carrying more than 7,000 gallons of anhydrous ammonia fell from a freeway ramp, spilling its lethal contents.

The incident, which left seven dead and nearly 200 injured, caused officials to rethink how to tackle chemical disasters and led to rules still in use today.

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Over forty years later, the route that ammonia truck took still snakes through a city that has doubled in size, leaving Houston vulnerable to a catastrophic accident

Just after 11 a.m. on May 11, 1976, a tanker truck carrying the dangerous chemical fell onto the Southwest Freeway from the 610 West Loop above. The driver had lost control of the rig and hit a support beam.

The National Transportation Safety Board later determined that the driver was perhaps not traveling at a safe speed. He barely missed landing on a car passing by. Not much was left from the truck in the aftermath.

Its 7,000-gallon load was not the standard cleaning product one would use at home.

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This was pure, undiluted industrial anhydrous ammonia that is used in heavy-duty chemical processes and is extremely deadly if mishandled.

The fumes that were released proved fatal for those who were too close. Freeway traffic was closed for three miles in all directions. Most nearby residents left their homes. Those who were close enough to detect the smell were told to relocate until the odor dissipated.

A recording of the KPRC-AM coverage of the event can be heard here. Reporter Bob Raleigh spoke to witnesses who saw the accident and confirmed fatalities at the scene with fire officials.

KHOU-TV reports from the scene show medics taking away burn victims and everyday Houstonians chipping in to help the recovery effort. One medic said he had 12 people in one ambulance.

There was almost no chance of survival for those caught in a cloud of ammonia that strong, and most greenery in the area later died.

Pictures from the Houston Post's archive are surreal. The news would make it around the world.

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The Post building, of course, was just steps away from the crash site, and the blast shook the four-story building. The Houston Chronicle, which has had printing presses at the site for some years, now occupies the renovated former Post building, after moving all its offices to the site over the winter.

The accident claimed seven lives, including six who died at the scene or shortly afterwards: David Randle Whiteman, 48; Grace Gillebaard, 33; Earl Davis, 26; Gordon D. McAdams, 40; Robert Wisnoski, 64, and truck driver William Gregory Schmidt, 28

Some people survived their exposure to the chemical but would live with lung damage.

Former beauty queen Karen Bijak, 27, died in 1979 of health complications stemming from the crash. She would be the seventh fatality.

Because of this deadly accident, hazardous materials in such large quantities are not allowed to be transported inside the 610 Loop. At the time the Houston Fire Department did not yet have a dedicated hazmat team, which today is a routine fixture at even minor chemical spills.