The investigation into the fire that destroyed two waste transfer buildings at Waste Management Tuesday night continued throughout the day Wednesday. Meanwhile, firefighters put out the last hot spots at the site.

An official cause has not been determined.

Firefighters were called back to the site at 3 a.m. today for additional flare-ups.

Clarks Grove Fire Chief Carl Anderson said his crew also was putting out hot spots just after noon Wednesday. All the garbage was soaked down.

The fire initially broke out Tuesday just after 8 p.m. in the transfer buildings across the roadway from the company’s office building. Truck maintenance personnel working in an adjacent building reported it to authorities.

Seven fire departments battled the blaze.

Officials said fire crews left around 1 a.m. Wednesday but were back putting out hot spots later in the morning.

The state fire marshal’s office is investigating the cause.

One destroyed building was for waste transfer and the second was for recycling and waste transfer. The waste is loaded on semis, which haul it to Iowa.

Information from the Freeborn County Sheriff’s Office stated that, though the cause of the fire is still undetermined, there is a possibility that the fire started from hot ash or something similar from a truck that unloaded about a half hour prior to reporting time.