A mysterious death on board United Airlines flight 95 is still under investigation. The plane was headed to Houston, Texas from Colorado when the death is believed to have occurred.

"A passenger died Tuesday night on a plane en route to Bush Intercontinental Airport. Investigators were dispatched to the airport about 11:30 p.m. after the plane landed, according to the Houston Police Department," reported the Houston Chronicle. "Police said the person died of apparent natural causes and no foul play was suspected. No other information about the case was released."

"A man collapsed in the aisle of the plane at around 9 p.m and CPR was administered," according to a report on the website ValueWalk.com. "A United Airlines spokeswoman confirmed that there was a medical emergency on board and emergency services met the flight after it landed around 11 p.m. The man was pronounced dead on arrival. Houston Police Department homicide detectives and the the Harris County Medical Examiner are investigating the cause of death."

According to television station KTRK, "Detectives say a person on United Airlines flight #95 died after the plane left Denver to Houston. It is unclear what caused the passenger's death."

The last time passenger was reported to have died on a United Airlines flight occurred less than six months ago, according to valuewalk.com. "The last in flight death reported on a United Airlines flight occurred in February 2014, on a flight from Hong Kong to Singapore.

"Staff were unaware that the passenger had passed away until the flight landed. After the incident a passenger accused staff of not responding quickly enough to his warning that the deceased appeared to be unconscious," the site reported. 

The Houston Fire Department responded to the scene when the plane landed. So far authorities have not released any information about the man's identity. The county coroner will examine the body to determine the cause of death.