A large chunk of ice fell through a roof of a house in Chino, San Bernardino County, California around 20:30 local time on November 4, 2017. A similar incident happened in 2006, just 3.2 km (2 miles) away.
Brandon Blanchard, the owner of the damaged home, said he was hanging out with his friends in a garage when his wife came out and said there had been "an explosion or something."
The owners searched the house and found a hole in the ceiling of their upstairs bathroom and several large chunks of ice in the bathtub.
Blanchard said he filled an incident report with the Chino Police Department, adding that the FAA is investigating the incident as the house is in a flight path for Los Angeles International Airport.
"The FAA has not yet concluded whether the ice came from an airliner," FAA spokesman Ian Gregor said. "The ice was clear, not blue, meaning that it could have formed on the outside of an airliner from a leak in its galley. Blue ice would have come from an airliner’s lavatory," he said.
"We are running radar replays to see which, if any, aircraft were flying over the area for a period of time before and after the homeowner says the incident occurred," Gregor said. "If we find aircraft were in the area, we will contact the operators to advise them to check their planes for possible water leaks."
A NWS spokesman said it is unlikely that the ice was a result of a weather phenomenon.
A megacryometeor is a very large chunk of ice which, despite sharing many textural, hydrochemical and isotopic features detected in large hailstones, is formed under unusual atmospheric conditions which clearly differ from those of the cumulonimbus cloud scenario (i.e. clear-sky conditions).
The research into cryometeors was pioneered by Jesús Martínez-Frías, a planetary geologist and astrobiologist at Institute of Geosciences (IGEO) in the Spanish National Research Council (CSIC) in Madrid, in January 2000 after ice chunks weighing up to 3 kg (6.6 pounds) rained on Spain out of cloudless skies for ten days.
Although officials will usually explain these phenomena in relation to a passing aircraft, megacryometeors have been reported as far back as 1849 and before the existence of aircraft.
The heaviest known so far had more than 50 kg (110 pounds). It fell down in Brazil.
Featured image: Roof damage after a large chunk of ice hits a house in Chino, California - November 2017. Credit: CBS Los Angeles