1. Cyclone Tauktae: The fifth strongest storm to hit the Arabian Sea since 1998 and the strongest tropical storm to hit Mumbai in at least five decades, Cyclone Tauktae took over 170 lives and damaged thousands of properties in Kerala, Karnataka, Goa, Maharashtra and Gujarat. Several parts of Mumbai witnessed waterlogging on May 17 as it received the highest amount of rainfall for a day in May since the maintaining of records began in the 19th century, A wind gust of 108kmph at Colaba was perhaps the highest recorded since 1948. Extreme weather conditions also led to road, rail, air traffic and power disruption. There was, however, no loss of lives recorded in Maximum City.

2. ONGC barge tragedy: In what can be called as India’s worst offshore disaster, a total of 86 personnel lost their lives due to the sinking of vessels deployed for Oil Natural Gas Corporation (ONGC) projects. So, what went wrong on May 17? The barges were not evacuated from the path of Cyclone Tauktae and four vessels---Barge Papaa–305, Barge Support Station-3, Barge Gal Constructor and ONGC’s Sagar Bhushan---went adrift in the high seas. There were over 800 people on board these vessels. The anchors of Barge Papaa-305, with 261 crewmen on board, gave way and over 70 crewmen drowned after it capsized. Indian Navy’s INS Kochi and INS Kolkata, three coast guard vessels, 14 other vessels owned by ONGC were deployed for the rescue operation. 

3. Landslides, house collapses: Incessant rains in July 2021 led to a series of landslides in Chembur and Vikhroli. At least 32 people were killed and several others injured after being trapped under the collapsed houses. In another incident, three people died after a building in Vikhroli collapsed following heavy rains. Seven more died in Vashi when a house wall collapsed. Nine hutment dwellers were killed after five shanties collapsed after a landslide in Vikhroli. National Disaster Response Force deployed teams to carry out rescue operations. Units of the Coast Guard, Indian Navy and the Indian Army too joined the rescue and relief efforts. 

4. Mumbai rains: The infamous Mumbai rains claimed at least 32 lives after a thunderstorm on July 19. The heavy downpour not only threw road and rail traffic out of gear, but also damaged goods worth crores as two-wheelers were washed away and so did several homes and shops, especially in the suburbs. In a shocking incident, a car was swallowed by a sinkhole in a matter of seconds outside a housing complex. The 2021 monsoon also marked the third consecutive year in which Mumbai received over 3000mm of rain. This year, the city saw three ‘extremely heavy’ rainfall days, receiving over 204.5mm in July. In December, with the unseasonal showers, Mumbai witnessed the highest December rainfall ever. 

5. High-rise fires: Two people were killed in a major fire outbreak in a 15-storey residential building in suburban Kandivali (West) on November 17. The fire started in a flat on the 14th floor of Hansa Heritage building on Mathuradas Road. Fire brigade designated it as a level 1 fire. In another incident, a 30-year-old security guard fell to death from the balcony of a flat located on the 19th floor of a 61-storey residential building in central Mumbai after a major fire broke out there on October 22. The blaze erupted on the 19th floor of the One Avighna Park building on Currey Road shortly before noon.