Heathrow reopens and chaos eases. But critics say the airport’s shutdown exposes UK vulnerability

LONDON (AP) — London Heathrow Airport said it was “fully operational” on Saturday, after an almost daylong closure sparked by an electrical substation fire. But thousands of passengers remained stuck, and airlines warned that severe disruption will last for days as they scramble to relocate planes and crews and get travelers to their destinations.

Friday’s travel mayhem raised concerns about Britain’s ability to withstand disasters or attacks on critical infrastructure. Inconvenienced passengers...