Last Thursday, 32 people on board the Limousine Express, route 284, were possibly exposed to COVID-19.
Officials say one of the passengers died shortly after the ride and tested positive for coronavirus.
Officials are trying to do contact tracing, but the bus line does not require phone numbers or email addresses from passengers.
The president of the bus line said they conducted temperature checks for everyone on board before they left El Paso.
The health department is asking bus riders to look out for COVID-19 symptoms, and recommends anyone on the bus to quarantine for 14 days.
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