California Department of Public Health

Occupational Health Branch

FATALITY ASSESSMENT AND CONTROL EVALUATION PROGRAM 

(CA/FACE) 

A maintenance diver died from hyperthermia as he was preparing to do 

routine maintenance on a water tank

Case Report: 20CA003 

SUMMARY

A maintenance diver died from hyperthermia as he was preparing to do routine maintenance 

on a 150,000 gallon steel water tank that was 150 feet tall. The three-person work crew was 

preparing to conduct routine maintenance inside the tank when the incident occurred. The 

victim had climbed 100 feet to the water tank catwalk when he was found collapsed by a coworker. The autopsy report indicated the victim died from a combination of hyperthermia and 

the presence of methamphetamine. The CA/FACE investigator determined that, in order to 

prevent future incidents, water tank maintenance companies should:

• Develop and implement a Heat Illness Prevention Plan.

• Implement a Workplace Supported Recovery Program using evidence-based policies and

programs to reduce multiple risk factors for substance use.

INTRODUCTION

On Wednesday, June 24, 2020, a 27-year-old male maintenance diver died from hyperthermia 

as he prepared to clean the inside of an aboveground water tank. The CA/FACE investigator 

received notification on July 8, 2020, from the Cal/OSHA Weekly Fatality Report. On April 17, 

2021, contact was made with the employer of the victim. Interviews were conducted via phone 

and email with the company general manager, and the co-worker and supervisor who were 

onsite the day of the incident. The county coroner, fire department, and sheriff’s department 

reports of the incident were also obtained and reviewed. 

EMPLOYER

The employer of the victim was a water tank maintenance company that had been in business 

for over 35 years and had six employees. The company provided commercial diving services to 

maintain water systems. On the day of the incident, there were three employees onsite. 
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WRITTEN SAFETY PROGRAMS AND TRAINING

The company had a written safe practices manual for the work being performed and a written 

Injury and Illness Prevention Program (IIPP) with all the required elements, but did not have a 

complete Heat Illness Prevention Plan. Before hire, all employees must have graduated from an 

accredited dive school and received certification. In addition, members of the dive maintenance 

team received annual and ongoing dive training from the founder of the company. All workers 

received periodic and on-the-job safety training from their supervisor, but this did not include 

in-depth heat illness prevention education. 

WORKER INFORMATION

The victim was a 27-year-old male maintenance diver who was hired by the company in January 

2020 but, due to COVID-19, his start date was delayed until June 1, 2020. According to the 

employer, he had received all required trainings and certifications prior to the incident. His 

previous work experience prior to this job is unknown.

WEATHER

The temperature and humidity at the time of the incident was 87 degrees Fahrenheit with 33% 

humidity, and a heat index of 90 degrees Fahrenheit [Weather Underground 2020].

INVESTIGATION

On the day of the incident, the victim, his co-worker, and onsite supervisor arrived at the 

worksite at approximately 7:30 a.m. Knowing the temperature would exceed 100 degrees 

Fahrenheit that day, the supervisor checked in with the crew to confirm the high heat forecast. 

He reminded them to drink lots of water throughout the day, and also witnessed them 

hydrating prior to the start of work. The victim and co-worker took multiple bottles of water 

(237 ounces total) with them up on the tower, but it is unknown how much they consumed. 

The supervisor mentioned that the water tank provided shade on portions of the catwalk for 

workers when needed. 

The victim was assigned to be the diver that day, performing maintenance inside the 150,000

gallon steel water tank. The co-worker worked as the tender and was responsible for dressing 

the diver before he enters the tank, controlling the hose assembly, and maintaining 

communications between the diver and the supervisor. The supervisor was planning to work 

from the ground, controlling the equipment. 

The victim and the co-worker climbed approximately 100 feet up a ladder to the catwalk, and 

then the victim began to set up hose lines. The co-worker then climbed another 40 feet to the 

top of the tank where he began setting up the hose lines needed to enter the tank. After he 

finished setting up the hoses on the catwalk, the victim was supposed to join the co-worker on 
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the top of the tank to get dressed for the dive. The supervisor on the ground tried to 

communicate with the victim through the radio but was unsuccessful, so he immediately 

stepped out of the trailer to visually check on him. Because the victim was partially hidden by 

the ladder and he couldn’t see him, the supervisor got on the radio and asked the co-worker to 

check on him. The co-worker climbed down from the top of the tank to the catwalk and found 

the victim slumped behind the ladder, unable to stand up on his own. When the co-worker 

lifted the victim up to lean against the railing, he began vomiting and then became 

unresponsive. The co-worker called the supervisor via cell phone and requested medical 

assistance, stating there was a medical issue with the victim. The supervisor told a facility 

maintenance worker to call for medical help and the fire department was dispatched at 10:47 

a.m. The supervisor then he climbed the catwalk to assist the co-worker with the victim. 

Realizing the victim was suffering from a heat-related injury, the supervisor and co-worker gave 

medical aid and tried to cool the victim by removing some of his clothing and pouring cool 

water from their water bottles onto his skin. 

The fire department arrived at the site at 10:52 a.m., and rescuers climbed the 100 feet to the 

catwalk and set up for a high angle technical rescue. It took approximately one hour to lower 

the victim from the catwalk to the awaiting transport units on the ground. No advanced life 

support (ALS) care was given during the technical rescue. Once on the ground, the victim was 

identified as pulseless and non-breathing. Rescuers started CPR and transported the victim by 

private ambulance approximately three miles to the nearest hospital. The victim arrived at the 

hospital at approximately 12:15 p.m. with a core temperature of 106.8 degrees Fahrenheit. As 

the emergency room staff treated the victim, he had a return of circulation followed by 

pulselessness several times before he was pronounced dead at 5:45 p.m. 

CAUSE OF DEATH

The cause of death, according to the death certificate, was the combined effects of heat 

exhaustion/heat stroke and acute methamphetamine toxicity. 

RECOMMENDATIONS

The CA/FACE investigator determined that, to prevent future incidents, water tank 

maintenance companies should: 

Recommendation #1: Develop and implement a Heat Illness Prevention Plan.

Discussion: On the day of this incident, the supervisor told everyone they would be working in 

high heat, reminded them to stay hydrated, and that portions of the water tank could provide 

shade. However, there was no written Heat Illness Prevention Plan, and heat illness prevention

was not included in worker trainings. 

A Heat Illness Prevention Plan can be integrated into the employer’s Injury and Illness 

Prevention Program or may be maintained separately, and should include:
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• Procedures for providing sufficient water 

• Procedures for providing access to shade 

• Monitoring weather and temperatures

• High-heat procedures

• Acclimatization methods 

• Emergency response

• Proper handling of sick employees

• Training all employees on the Heat Injury and Illness Prevention Plan

It is likely that several factors contributed to the risk of hyperthermia in this incident, including 

direct thermal effects, heat radiation from the structure, and physical exertion. The victim 

reported he had hydrated prior to beginning work that day, but it is unknown if he had 

acclimatized to the heat during the days prior to the start of this job. Methamphetamine also 

likely increased the risk of hyperthermia by impairing the ability of the victim to sweat and 

dissipate heat. Individuals with heat stroke and elevated body temperature need to be treated 

as soon as possible. In this incident, the co-worker poured water onto the victim’s skin, but he 

was not treated with emergency cooling measures (ice packs/wet sheets or towels) until he 

arrived at the hospital emergency room almost three hours after he collapsed. 

Recommendation #2: Implement a Workplace Supported Recovery Program using evidencebased policies and programs to reduce multiple risk factors for substance use. 

Discussion: In this case, the post-mortem toxicology report was positive for methamphetamine. 

The coroner’s report stated that the cause of death was the combined effects of heat 

exhaustion/heat stroke and acute methamphetamine toxicity. Among several mechanisms, 

methamphetamine increases body temperature by promoting heat generation and retention 

and suppressing responses that would facilitate heat dissipation, and likely contributed to the 

risk of heat stroke. 

In this incident, there was no program to ensure that employees who work at heights or with 

dangerous equipment are free from drugs that could endanger themselves or others. Preemployment, periodic, and random drug testing programs can be effective in identifying 

employees who are at risk of drug-related work impairment or at greater risk of injury and 

illness. Some dive training programs, such as National Oceanic and Atmospheric Administration

(NOAA), require a drug test prior to certification with subsequent random drug testing after 

hire. Employers implementing applicant or employee drug testing programs should develop and 

communicate clear policies that are permissible under the law, and legal consultation is 

recommended. Had such a program been in place, the risk of methamphetamine contributing 

to his death may have been minimized.

As described by the National Institute for Occupational Safety and Health (NIOSH), a Workplace 

Supported Recovery (WSR) Program can be valuable in preventing and responding to substance 
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abuse problems in the workplace (see Centers for Disease Control and Prevention – Workplace 

Supported Recovery Program). A WSR Program can: 

• Prevent work-related injuries and illnesses that could lead to the initiation of substance 

misuse. 

• Decrease difficult working conditions or work demands that might lead to daily or 

recurrent pain. 

• Promote the use of alternatives to opioids for pain management associated with a 

workplace injury or illness. 

• Provide information and access to care for a substance use disorder when it is needed, 

including access to medication-based or medication-assisted treatment, together with 

individual counseling. 

• Support second-chance employment. 

• Provide workplace accommodations and other return-to-work assistance. 

• Provide peer support and peer coaching to bolster the social supports available to 

workers in recovery. 

• Promote a work culture and climate that is supportive of workers in recovery (for 

example, awareness building, stigma reduction, and alcohol-free and health-focused 

work social events). 

Workplaces can engage in several activities to mitigate the risk factors for initiation or 

perpetuation of a substance use disorder, help maximize the likelihood that employees in need 

will seek treatment, and support employees in their recovery efforts. 

Policy. Workplace policies regarding substance use should be clear and transparent, defining 

the reasons for the policy, the prohibited substances and behaviors, the persons covered by the 

policy, and disciplinary consequences and appeals. Workplace substance use policies should be 

sensitive to the nature of recovery efforts. For example, a recovery-supportive policy will 

recognize that recovery may involve one or more recurrences and, therefore, additional or 

modified treatment. Also, because employment increases the likelihood of entering treatment 

and maintaining recovery efforts, workplace policies should support recovering individuals 

attempting to maintain employment and those hoping to enter or return to the workforce.

Education. Recovery-supportive workplaces can provide training to all supervisors and 

employees. Trainings cover types of drugs (including alcohol), the health impacts of misusing 

them, how substance use can impact behavior, performance at work, and implementation of 

workplace policies involving substance use. In-person training is recommended as a best 

practice and online training should be provided when in-person training is not feasible.

Work environment. Recovery-supportive workplaces evaluate their work environments to 

minimize adverse working conditions that may contribute to higher levels of employee 

substance misuse. These include but are not limited to excessive work demands, exposure to 

interpersonal aggression at work, and dangerous working conditions. Workplaces may promote 

a quality work environment by establishing and maintaining potentially protective working 
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conditions, such as fair and equitable treatment, respectful supervision, and promotion of 

supportive social connections and friendships among co-workers.

Stigma reduction. Individuals with a substance use disorder experience extreme levels of 

stigmatization (negative attitudes and stereotypes) that lead to prejudice, discrimination, social 

exclusion, and limited opportunities to participate fully in employment and other life roles. 

Stigmatization is also experienced by individuals who have recovered from a substance use 

disorder. Therefore, visible educational materials, as well as consistent discussions of the actual 

nature of substance use disorders, treatment, and recovery, may help reduce stigma and 

encourage entry into treatment and recovery. A key talking point in these materials and 

discussions is that a substance use disorder is not a moral failing and recovery is possible. The 

Center on Addiction provides recommendations for reducing stigma related to substance use 

disorders. 

Resources and support. Inform employees about resources available through the employer or 

union for the treatment of substance misuse and disorders and recovery support. These 

resources may be part of a company employee assistance program and health insurance. If an 

employee assistance program and health insurance are not available, an information sheet on 

available resources in the community can be made available. 

• Employers should consider evaluating their employee assistance and health insurance 

programs to make sure they have adequately trained personnel to deal effectively with 

substance use problems and have adequate coverage for multiple episodes of 

treatment (inpatient, outpatient, medication-assisted treatment), long-term follow-up, 

and recovery support (such as recovery coaching).

• Support programs utilizing co-workers or peers, with appropriate training, may offer 

valuable and confidential support such as sharing information and providing referrals, 

advocacy, and accountability. Peers are not usually formally trained to provide clinical 

services, but their skills and support may help lower barriers for seeking help and 

following through with treatment. Peer-based approaches or links to peer-based 

organizations and their programs may be of significant value to workers and employers 

when developing WSR programs.

Sensitivity to disparities. Workers across all age ranges, races, ethnicities, and organizational 

levels within the workforce can engage in substance misuse and develop substance use 

disorders. However, barriers to treatment and willingness to enter treatment and recovery may 

vary across these groups, based on factors such as religious and cultural norms or expectations, 

family history, age, and education. Employers should consider having expertise available in their 

employee assistance or health insurance programs to address differences across various 

demographic groups as needed.

Health and well-being programs. Providing programs that promote and support employee 

health, well-being, and work-life fit, as well as teach functional coping skills, may help 

employees develop and maintain their recovery efforts by building recovery capital.
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Employment. Employment provides economic stability, a meaningful social role, and often 

direct access to treatment and recovery services. Employment also provides relevant sources of 

recovery capital that can motivate and maintain a desire for treatment and recovery. Recoverysupportive employers aim to preserve employment for those with a substance use disorder and 

provide second-chance employment for recovering individuals attempting to enter or reenter 

the workforce.

Workplace substance use climate. Evaluate and reduce current levels of physical availability of 

substances during the workday, as well as workplace norms and drinking rituals that support 

substance use. Physical availability includes the ease of obtaining alcohol and other drugs at 

work, bringing alcohol or other drugs into the workplace, or using substances during work 

hours or breaks. Substance use norms include descriptive norms, which represent the extent to 

which workers use substances while at work or work while impaired. Substance use norms also 

include injunctive norms, which represent the extent to which workers approve of using 

substances while at work or working while impaired. Although after-work drinking rituals are a 

way for co-workers to unwind and develop friendships, they can undermine the recovery 

efforts of co-workers who want to avoid alcohol use but, as a result, may experience social 

exclusion at work for not participating.

Focus on the future workforce. Roughly 90% of individuals with severe substance use disorders 

began using before the age of 18. Workplaces that employ adolescents and focus on prevention 

efforts aimed at employee substance misuse may circumvent problems in the next generation 

of workers. Additionally, a comprehensive WSR program could include prevention-focused 

resources specific to employees that are parents of adolescents.

REFERENCES 

Cal/OSHA §3395. Heat Illness Prevention in Outdoor Places of Employment 

https://www.dir.ca.gov/title8/3395.html

CDC NIOSH Workplace Supported Recovery Program.

https://www.cdc.gov/niosh/topics/opioids/wsrp/default.html 

Matsumoto RR, Seminerio MJ, Turner RC, Robson MJ, Nguyen L, Miller DB, O'Callaghan JP. 

Methamphetamine-induced toxicity: an updated review on issues related to hyperthermia. 

Pharmacol Ther. 2014 Oct;144(1):28-40. 

NIOSH/CDC-Criteria for a Recommended Standard Occupational Exposure to Heat and Hot 

Environments. (NIOSH) Publication No. 2016-106. https://www.cdc.gov/niosh/docs/2016-

106/default.html 

NOAA Scientific Diver Training and Certification Requirements https://www.omao.noaa.gov 

Substance Abuse and Mental Health Services Administration, Drug-Free Workplace Programs 

https://www.samhsa.gov/workplace
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Weather Underground [2020]. June 24, 2020 Weather History in Fresno, California, United 

States. 

EXHIBITS: 

Exhibit 1. The 150-foot water tower being serviced.

Exhibit # 2. Rescuers lowering the victim from the catwalk (photo courtesy ABC30).
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_____________________________ ______________________________

TJ Welch Robert Harrison, MD, MPH

Safety Consultant FACE Project Officer

 

_____________________________ October 3, 2022

Laura Styles 

FACE Research Scientist 

 

 

 

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FATALITY ASSESSMENT AND CONTROL EVALUATION PROGRAM

The California Department of Public Health, in cooperation with the Public Health Institute 

and the National Institute for Occupational Safety and Health (NIOSH), conducts 

investigations of work-related fatalities. The goal of the CA/FACE program is to prevent fatal 

work injuries. CA/FACE aims to achieve this goal by studying the work environment, the 

worker, the task the worker was performing, the tools the worker was using, the energy 

exchange resulting in fatal injury, and the role of management in controlling how these 

factors interact. NIOSH-funded, state-based FACE programs include: California, Kentucky,

Louisiana, Massachusetts, Michigan, New York, Oregon, and Washington.

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Additional information regarding the CA/FACE program is available from:

California FACE Program

California Department of Public Health

Occupational Health Branch

850 Marina Bay Parkway, Building P, Third Floor

Richmond, CA 94804

www.cdph.ca.gov/face