Melbourne insurance offices have been overloaded with calls from householders and businesses reporting damage to buildings and vehicles after a “supercell thunderstorm” hit Victoria on Saturday and heavy rain fell yesterday.

Major city buildings, including Southern Cross Station, Etihad Stadium and the Arts Centre, have reported extensive damage from Saturday’s storm, which caused flash flooding and dumped large hailstones on the city. Two people are in intensive care and thousands of others reportedly suffered bruising from hailstones.

Up to 40mm of rain was dumped on Melbourne in 30 minutes again yesterday, causing more damage, and the Bureau of Meteorology says heavy winds are expected later today. Electricity to up to 100,000 homes was cut, and 15 families had to be evacuated from their damaged homes.

CGU spokesman Iwona Polski says few customers have so far contacted the company, although the insurer is bracing for a busy Tuesday.

“Most will call their broker first, and today being a public holiday in Victoria means we’ll be getting most claims coming through tomorrow as people return home and businesses return to work,” she told insuranceNEWS.com.au. “So far the few hundred calls we’ve had have been split between motor and home damage.”

Zurich Insurance Claims Manager Southern Region Darren Trott says his Melbourne office has a full complement of claims staff on duty despite the holiday, and he expects tomorrow to be even busier.

“One of the major loss adjusters told us they’re experiencing a record number of calls, and the others say they’re already very busy,” he told insuranceNEWS.com.au. “We’re getting a lot of reports of damage across all classes.”

Mr Trott says some strata apartments have suffered extensive water damage, “with water cascading from the top floor right through the whole complex”.