BANGKOK (Reuters) - Thailand resumed flights on Saturday to its southern provinces, as the first tropical storm in 30 years slowed and headed into the Andaman Sea, leaving behind a trail of homes damaged by fallen trees or blown-off roofs, and disrupted power networks. Before tropical storm Pabuk hit land in Nakhon Si Thammarat , arriving from the Gulf of Thailand, airports had shut in the province and nearby Surat Thani and the holiday island of Koh Samui, with all flights cancelled. But on Saturday, the storm lost speed and was downgraded to a depression as it moved off land, weather officials said, although they maintained warnings of torrential rain and possible flash floods in nine provinces. “The strong winds are forecast with waves up to 3 to 5 meters high in both the Gulf and in the Andaman Sea,” the Thai Meteorological Department said in a statement, urging ships to keep to shore and highlighting the risk of sudden water surges. Bangkok Airways, which has a monopoly at the Koh Samui airport, resumed normal operations early on Saturday and added extra flights to assist stranded passengers. The airports at Nakhon Si Thammarat and Surat Thani will resume operations at noon. Most ferry services to Thailand’s southern holiday islands have resumed following suspension for the storm. Over the past few days, more than 28,000 people have been evacuated into shelters across seven provinces, the Department of Disaster Prevention and Mitigation said in a daily tally on Saturday. Authorities have recorded just one death, after a fishing boat capsized in strong winds near the coast of Pattani province, leaving another of the crew missing, though four more were safe. PTT Exploration and Production Pcl, a unit of state-owned PTT, said it expected to resume operations of oil rigs at Bongkot and Erawan, two of Thailand’s biggest gas fields in the Gulf of Thailand, on Sunday. It had suspended operations there since Monday and brought staff inland.