May 17th, 1994: Fire engulfs Honduras prison

A fire in an overcrowded Honduras prison kills 103 people on May 17, 1994. An overheated refrigerator motor sparked the horrible blaze that raced through the outdated jail. Only a year earlier, a gang fight at the same prison had left nearly 70 people dead.

The prison, in San Pedro Sula, 100 miles north of the Honduran capital of Tegucigalpa, was largely devoted to housing gang members arrested in a recent crackdown. This new emphasis on jailing gang members resulted in a prison population of nearly 2,000, although the structure was built to accommodate only 800. The fire and explosion took place in a cell block that housed 186 prisoners belonging to the Mara Salvatrucha gang, also known as MS-13. The fire started in one of two small refrigerators located in the cell block at about 1:30 a.m. Prisoner Jose Lopez reported, “Everything happened fast. We woke up with our clothes and our beds in flames.” Guards reported that they had to fire their guns in the air in order to keep the prisoners from attacking the firefighters and escaping. Inmates claimed that the guards were preventing the prisoners from fleeing the fire.

As news of the fire became public, relatives of the prisoners began gathering outside the prison. Officials then placed the bodies of the dead in rows on the ground for identification, which was often made through their elaborate gang-related tattoos, before refrigerated trucks transported them to a morgue.

The Honduran government continued its anti-gang activity in the wake of the tragedy, but also took steps to prevent prison overcrowding.


May 6, 1937:  Hindenburg explodes in New Jersey

On this day in 1937, the German airship Hindenburg, the largest dirigible ever built, explodes as it arrives in Lakehurst, New Jersey. Thirty-six people died in the fiery accident that has since become iconic, in part because of the live radio broadcast of the disaster.

The dirigible was built to be the fastest, largest and most luxurious flying vessel of its time. It was more than 800 feet long, had a range of 8,000 miles, could carry 97 passengers and had a state-of-the-art Mercedes-Benz engine. It was filled with 7 million cubic feet of hydrogen, even though helium was known to be far safer, because it made the flying ship more maneuverable.

The Hindenburg had made 10 successful ocean crossings the year before and was held up by Germany’s Nazi government as a symbol of national pride. Flying at a speed of 85 miles per hour, the Hindenburg was scheduled to arrive in New Jersey at 5 a.m. on May 6. However, weather conditions pushed the arrival back to the late afternoon and then rain further delayed the docking at Lakehurst. When the dirigible was finally cleared to dock, Captain Max Pruss brought the ship in too fast and had to order a reverse engine thrust. At 7:20 p.m., a gas leak was noticed. Within minutes, the tail blew up, sending flames hundreds of feet in the air and as far down as the ground below.

A chain reaction caused the entire vessel to burn instantly. The nearly 1,000 spectators awaiting the Hindenburg‘s arrival felt the heat from a mile away. Some on the blimp attempted to jump for the landing cables at the docking station but most died when they missed. Others waited to jump until the blimp was closer to the ground as it fell. Those who were not critically injured from burns often suffered broken bones from the jump. Fifty-six people managed to survive.

On WLS radio, announcer Herbert Morrison gave an unforgettably harrowing live account of the disaster, “Oh, oh, oh. It’s burst into flames. Get out of the way, please . . . this is terrible . . . it’s burning, bursting into flames, and is falling . . . Oh! This is one of the worst . . . it’s a terrific sight . . .oh, the humanity.”


Aluminum Phosphide-Based Fumigants as an Ignition Source


John L. Schumacher, MChE, PE, CFI, CFPS
Zachary J. Jason, PE, CFEI
Advanced Engineering Investigations Corporation, USA

Presented at International Symposium on Fire Investigation, 2012


Raw agricultural commodities, such as corn, soybean, rice and wheat, are typically stored in bins and silos prior to shipment. During storage, it is often necessary to protect the commodities from damage by insects and pests. A common protection method utilized is the addition of solid fumigant pellets or tablets to the commodity.

One of the most common solid fumigants employed is a blend of aluminum phosphide, ammonium carbamate and other inert ingredients. Aluminum phosphide reacts with atmospheric water and moisture in the commodity based on the following equation:

AlP + 3H2O = Al(OH)3 + PH3 + Heat

The reaction yields phosphine gas (PH3), which is highly toxic to insects, pests and humans. The reaction is exothermic, which means heat is generated alongside the other products. Phosphine gas has a lower flammable limit (LFL) of about 1.8% gas in air and can ignite spontaneously at concentrations above the LFL. The ammonium carbamate is added to the mixture to reduce the potential fire hazard by generating ammonia and carbon dioxide, which act as inerting gases. The carbon dioxide reduces the tendency of phosphine to auto-ignite in air. The decomposition reaction is as follows:

NH2COONH4 = 2NH3 + CO2

Improper application of the fumigant tablets or pellets can lead to fires. This paper provides basic product information, and discusses the chemistry, application methods, previous testing, and ignition scenarios associated with solid fumigants containing aluminum phosphide. A case study of a fire that occurred in a metal grain bin containing wheat will be presented.

Presented at International Symposium on Fire Investigation, 2012