HOUSTON — An American Airlines flight from Brazil to Dallas was diverted to Houston on Wednesday after a 25-year-old passenger became ill and died aboard the aircraft, police said.   

Airport officials summoned homicide detectives to George Bush Intercontinental Airport just before dawn after learning that American Flight 962 was coming to Houston because of a medical emergency involving a passenger. The passenger was declared dead after the plane landed, authorities said.

“There was no sign of trauma,” and no foul play is suspected, Houston police spokeswoman Jodi Silva said. An autopsy will be done, she said.

The name of the passenger, a woman, wasn’t immediately released, and American Airlines spokesman Matt Miller said the airline couldn’t provide any information about her.

According to authorities, the Boeing 777 left Sao Paolo at 1:12 a.m. with 220 passengers and a crew of 14 bound for Dallas-Fort Worth International Airport. When the woman went into medical distress, the flight crew, along with a doctor who happened to be on board, began performing emergency procedures, and the plane was diverted to Houston.

The plane landed in Houston at 6:34 a.m., left the city about 2½ hours later and finally arrived in Dallas at 10:25 a.m.

Federal law requires a defibrillator on every flight with a maximum payload capacity of 7,500 pounds, a rule that covers major airliners, Federal Aviation Administration spokeswoman Laura Brown said. It also requires flight attendants to have CPR and defibrillator training at least once every two years.

In addition, American is one of the few airlines with trained medical professionals on staff, Miller said. Doctors are on call 24 hours a day and available to work with flight crews.

While onboard deaths are not unheard of, it’s not clear how many there are. The FAA does not keep track, Brown said.

A Vanderbilt University study published in 2003 based on a review of an unidentified major airline showed 1.52 “medical diversions” for every billion passenger miles flown. Another study published the same year from George Washington University put the number of deaths at one unidentified airline for all of 1999 at 0.1 per million passengers.