Time seemed to have stopped inside the main control room for the Fukushima Daiichi nuclear power plant's crippled Nos. 3 and 4 reactors -- that is how Kyodo News reporters felt when they recently became the first journalists to enter the facility since the 2011 nuclear meltdowns there.

The control room's interior has been left almost untouched since the disaster. Handwriting was found on the wall near an instrument that used to measure the No. 3 reactor's water levels, showing the urgency faced by some 10 workers there at the time of the crisis.

"We don't write (on the wall) under a normal situation, so it indicates it was an emergency," said an official of the plant's operator, Tokyo Electric Power Company Holdings Inc.

The nuclear crisis was triggered by the magnitude 9.0 earthquake and ensuing tsunami that flooded the facility on the Pacific Coast of Japan on March 11, 2011.

The No. 3 reactor suffered a fuel meltdown and a hydrogen explosion, while the No. 4 reactor, which did not have nuclear fuel inside, also exploded due to a hydrogen inflow from the nearby reactor.

In February 2014, TEPCO showed the media the control room for the Nos. 1 and 2 reactors, which also suffered meltdowns, but had kept the control room for the Nos. 3 and 4 closed due to high levels of radiation in the area.

Radiation levels inside the control room for Nos. 3 and 4, whose floor is now covered by special sheets, was 6 microsieverts per hour, which contrasts with 0.037 microsievert per hour in Tokyo's Shinjuku Ward on Sunday.

The room, which now has only a few lights, is no longer in use as its functions have been transferred to a quake-resistant building.

Following the crisis, which equaled the severity of the 1986 Chernobyl disaster, some 160,000 people were evacuated and more than 40,000 remained displaced as of late September.